Officially In. .

[email] following... Geofavor, please post the link to the physics thread. Thanks [/email]

Tobiee:
[email] following... Geofavor, please post the link to the physics thread. Thanks [/email]

I'm afraid there isn't a physics thread yet

Geofavor:

I'm afraid there isn't a physics thread yet

[email] Okay, what about maths? Kindly mention my i.d, when you(or anyone) create one.(physics) Thanks. [/email]

icecalm:
Mathefaro, please help us form some questions from the topics in (A) and (B), i'm seriously occupied at this moment. Thanks

Let me help post some since u are very occupied.

SECTION A

1: Almost the entire mass of an atom is
concentrated in the__________.

A. proton

B. electrons

C. nucleus

D. neutrons

2: Electron was discovered
by___________.
A. Chadwick
B. Thomson
C. Goldstein
D. Borh

3: An atom has a mass number of 23
and atomic number 11. The number of protons
are_________.
A. 11
B. 12
C. 23
D. 44

4: The mass of the atom is determined
by________.
A. neutrons
B. neutron and proton
C. electron
D. electron and neutron

5: The K, L and M shells of an atom are
full. Its atomic number is_______.
A. 18
B. 20
C. 10
D. 12

6: Which of the air pressures is
appropriate for the production of cathode rays in
the discharge tube?
A. 1 cm Hg
B. 1 mm Hg
C. 0.001 cm Hg
D. 0.001 mm Hg

7: Cathode rays are deflected
towards__________.
A. positive electrode
B. negative electrode
C. both electrodes
D. none of the electrodes

8: The absolute charge of an electron
is___________.
A. - 1.6 x 10-19 C
B. + 1.6 x 10-19 C
C. 1.6 x 10-19 C
D. 16 x 10-19 C

9: The proton is heavier than an
electron by___________.
A. 1850 times
B. 1840 times
C. 1000 times
D. 100 times

10: Carbon-12 atom has_______________.
A. 6 electrons, 6 protons, 6 neutrons
B. 6 electrons, 12 protons, 6 neutrons
C. 12 electrons, 6 protons, 6 neutrons
D. 18 electrons, 6 protons and 6 neutrons

11: Chadwick got the Nobel Prize for the
discovery of __________.
A. protons
B. neutrons
C. electrons
D. mesons

12: Mass number is equal to
the_________.
A. number of protons + number of electrons
B. number of protons + number of neutrons
C. number of neutrons + number of electrons
D. number of electrons

13: The element X has 2 valence
electrons. It is a____________.
A. metal
B. non-metal
C. metalloid
D . gas

14: The volume of the nucleus of an
atom when compared to the extra nuclear part
is_________.
A. bigger
B. smaller
C. same size
D. unpredictable

15: In Rutherford's alpha-scattering
experiment, a foil of element that was used
_______________.
A. gold
B. silver
C. aluminum
D. magnesium

16: An element has an electronic
configuration of 2, 8, 7. Its valency is
A. 1
B. 7
C. 17
D. 8

17: The other name of H(1,1) is _________
A. protium
B. tritium
C. deuterium
D. proton

18: During a chemical reaction, atomic
number_________.
A. changes
B. remains same
C. changes and then is restored
D. changes alternately

19: The fixed circular paths around the
nucleus are called_________.
A. orbits
B. orbitals
C. nucleons
D. mesons

20. Almost the entire mass of an atom is
concentrated in the
1. protons.
2. electrons.
3. neutrons.
4. nucleus.

21. All ions of an element have the same
1. atomic number.
2. number of electrons.
3. number of protons.
4. both option A. and C.

22. The mass of the atom is determined by
1. proton.
2. electrons.
3. neutron and proton.
4. electron and proton.

23. The absolute charge of an electron is
1. - 1.6 × 10 -19 C.
2. + 1.6 × 10 -19 C.
3. 1.6 × 10 -19 C.
4. none of above

24. The fixed circular paths around the nucleus are
called
1. orbits.
2. orbitals.
3. mesons.
4. nucleus.

25. According to the Bohr model, an electron gains
or losses energy only by
1. moving faster or slower in an allowed orbit.
2. jumping from one allowed orbit to another.
3. being completely removed from an atom.
4. jumping from one atom to another atom.

26. The number of rings in the Bohr model of any
element is determined by what?
1. Column number on periodic table.
2. Atomic mass.
3. Row number on periodic table.
4. Atomic number.

27. How many valence electrons would be found in
an atom with the atomic number of 51?
1. 5.
2. 51.
3. 8.
4. none of above.

28. The Bohr model of the atom
1.
explained the color lines in the hydrogen
spectrum.
2.
could not explain the line spectrum of atoms
larger than hydrogen.
3.
had some made-up rules without explanations.
4. all of the above.

29. Maximum number of electrons in a sub-shell with
l = 3 and n = 4 is
1. 10.
2. 14.
3. 20.
4. 8.

30. Which of the following statements is not part of
Dalton's atomic theory?
1. All matter is composed of atoms.
2. Atoms can combine to form compounds.
3.
Atoms of different elements are quite different.
4. An atom contains a dense central nucleus.

31. Atoms with fewer than 4 valence electrons are
1. insulator.
2. semi-conductor.
3. conductor.
4. none of these.

32. Atoms have no electric charge because they
1.
have an equal number of charged and non
charged particles.
2. have neutrons in their nuclei.
3.
have an equal number of neutrons and protons.
4.
have an equal number of electrons and protons.

33. Two different isotopes of an element have
different
1. numbers of neutrons.
2. numbers of electrons.
3. atomic number.
4. numbers of protons.

34. What is the mass number of an element that has
19 protons, 19 electrons, and 20 neutrons?
1. 19.
2. 39.
3. 38.
4. 20.

35. Which of the following statements is not true?
1. A s orbital can hold two electrons.
2. A d orbital can hold ten electrons.
3. A f orbital can hold three electrons.
4. A p orbital can hold six electrons.

36. The drawback of Dalton's atomic structure is
that, it says
1.
the atoms can neither be created nor be
destroyed.
2. unique nature of atom.
3.
most of the volume of an atom is empty space.
4. none of these.

37. The electron configuration of copper is
1. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 8, 4s 1 4p 2.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 10, 4s 1.
3. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 9, 4s 2.
4. none of above.

38. Silicon has
1. four valence electrons.
2. eight valence electrons.
3. two valence electrons.
4. none of above.

39. The electron configuration of sulfur atom is
1. 2, 8, 6.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6.
3. 2, 8, 2.
4. none of these.

NB: These questions are from only one topic (section A) out of almost 6 or 7 topics as given by Geofavor. Pls let s attend to it urgently so that I can post more questions on other topics.

OluchiDelly:

Nice one there, thanks for coming to the rescue

OluchiDelly:

Let me help post some since u are very occupied.

okay, thanks a lot.

Oluchidelly, well done.

C. B. A. B. A. Don't know. A. C. B. A. B. B. A. B. C. A. C. B. B. D. 4: 3: 4: 2 :1 3: 4: 4: 1: 4: 3: 4: 1: 2: 3: 1: 4: 1: 1:

A new students is in,I've been following this thread for a month,and I can see you guys are performing tremendously...

Icecalm, hope all is well?

1:c,2:b,3:b,4:b,5:a,6:b,7:a,8:c,9:b,10:a,11:b,12:b,13:a,15:a,16:a,17:a,19:b,20:4,21:4,22:3,24:2,32:4,33:1,34:2,35:3,36:1,37:4,38:3,39:2....that's what I know sha

[b][/b]

OluchiDelly:

SECTION A

1: Almost the entire mass of an atom is
concentrated in the__________.

A. proton

B. electrons

C. nucleus

D. neutrons

2: Electron was discovered
by___________.
A. Chadwick
B. Thomson
C. Goldstein
D. Borh

3: An atom has a mass number of 23
and atomic number 11. The number of protons
are_________.
A. 11
B. 12
C. 23
D. 44

4: The mass of the atom is determined
by________.
A. neutrons
B. neutron and proton
C. electron
D. electron and neutron

5: The K, L and M shells of an atom are
full. Its atomic number is_______.
A. 18
B. 20
C. 10
D. 12

6: Which of the air pressures is
appropriate for the production of cathode rays in
the discharge tube?
A. 1 cm Hg
B. 1 mm Hg
C. 0.001 cm Hg
D. 0.001 mm Hg

7: Cathode rays are deflected
towards__________.
A. positive electrode
B. negative electrode
C. both electrodes
D. none of the electrodes

8: The absolute charge of an electron
is___________.
A. - 1.6 x 10-19 C
B. + 1.6 x 10-19 C
C. 1.6 x 10-19 C
D. 16 x 10-19 C

9: The proton is heavier than an
electron by___________.
A. 1850 times
B. 1840 times
C. 1000 times
D. 100 times

10: Carbon-12 atom has_______________.
A. 6 electrons, 6 protons, 6 neutrons
B. 6 electrons, 12 protons, 6 neutrons
C. 12 electrons, 6 protons, 6 neutrons
D. 18 electrons, 6 protons and 6 neutrons

11: Chadwick got the Nobel Prize for the
discovery of __________.
A. protons
B. neutrons
C. electrons
D. mesons

12: Mass number is equal to
the_________.
A. number of protons + number of electrons
B. number of protons + number of neutrons
C. number of neutrons + number of electrons
D. number of electrons

13: The element X has 2 valence
electrons. It is a____________.
A. metal
B. non-metal
C. metalloid
D . gas

14: The volume of the nucleus of an
atom when compared to the extra nuclear part
is_________.
A. bigger
B. smaller
C. same size
D. unpredictable

15: In Rutherford's alpha-scattering
experiment, a foil of element that was used
_______________.
A. gold
B. silver
C. aluminum
D. magnesium

16: An element has an electronic
configuration of 2, 8, 7. Its valency is
A. 1
B. 7
C. 17
D. 8

17: The other name of H(1,1) is _________
A. protium
B. tritium
C. deuterium
D. proton

18: During a chemical reaction, atomic
number_________.
A. changes
B. remains same
C. changes and then is restored
D. changes alternately

19: The fixed circular paths around the
nucleus are called_________.
A. orbits
B. orbitals
C. nucleons
D. mesons

20. Almost the entire mass of an atom is
concentrated in the
1. protons.
2. electrons.
3. neutrons.
4. nucleus.

21. All ions of an element have the same
1. atomic number.
2. number of electrons.
3. number of protons.
4. both option A. and C.

22. The mass of the atom is determined by
1. proton.
2. electrons.
3. neutron and proton.
4. electron and proton.

23. The absolute charge of an electron is
1. - 1.6 × 10 -19 C.
2. + 1.6 × 10 -19 C.
3. 1.6 × 10 -19 C.
4. none of above

24. The fixed circular paths around the nucleus are
called
1. orbits.
2. orbitals.
3. mesons.
4. nucleus.

25. According to the Bohr model, an electron gains
or losses energy only by
1. moving faster or slower in an allowed orbit.
2. jumping from one allowed orbit to another.
3. being completely removed from an atom.
4. jumping from one atom to another atom.

26. The number of rings in the Bohr model of any
element is determined by what?
1. Column number on periodic table.
2. Atomic mass.
3. Row number on periodic table.
4. Atomic number.

27. How many valence electrons would be found in
an atom with the atomic number of 51?
1. 5.
2. 51.
3. 8.
4. none of above.

28. The Bohr model of the atom
1.
explained the color lines in the hydrogen
spectrum.
2.
could not explain the line spectrum of atoms
larger than hydrogen.
3.
had some made-up rules without explanations.
4. all of the above.

29. Maximum number of electrons in a sub-shell with
l = 3 and n = 4 is
1. 10.
2. 14.
3. 20.
4. 8.

30. Which of the following statements is not part of
Dalton's atomic theory?
1. All matter is composed of atoms.
2. Atoms can combine to form compounds.
3.
Atoms of different elements are quite different.
4. An atom contains a dense central nucleus.

31. Atoms with fewer than 4 valence electrons are
1. insulator.
2. semi-conductor.
3. conductor.
4. none of these.

32. Atoms have no electric charge because they
1.
have an equal number of charged and non
charged particles.
2. have neutrons in their nuclei.
3.
have an equal number of neutrons and protons.
4.
have an equal number of electrons and protons.

33. Two different isotopes of an element have
different
1. numbers of neutrons.
2. numbers of electrons.
3. atomic number.
4. numbers of protons.

34. What is the mass number of an element that has
19 protons, 19 electrons, and 20 neutrons?
1. 19.
2. 39.
3. 38.
4. 20.

35. Which of the following statements is not true?
1. A s orbital can hold two electrons.
2. A d orbital can hold ten electrons.
3. A f orbital can hold three electrons.
4. A p orbital can hold six electrons.

36. The drawback of Dalton's atomic structure is
that, it says
1.
the atoms can neither be created nor be
destroyed.
2. unique nature of atom.
3.
most of the volume of an atom is empty space.
4. none of these.

37. The electron configuration of copper is
1. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 8, 4s 1 4p 2.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 10, 4s 1.
3. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 9, 4s 2.
4. none of above.

38. Silicon has
1. four valence electrons.
2. eight valence electrons.
3. two valence electrons.
4. none of above.

39. The electron configuration of sulfur atom is
1. 2, 8, 6.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6.
3. 2, 8, 2.
4. none of these.

NB: These questions are from only one topic (section A) out of almost 6 or 7 topics as given by Geofavor. Pls let s attend to it urgently so that I can post more questions on other topics.

Nice one poster[b]

OluchiDelly:

SECTION A

1: Almost the entire mass of an atom is
concentrated in the__________.

A. proton

B. electrons

C. nucleus

D. neutrons

2: Electron was discovered
by___________.
A. Chadwick
B. Thomson
C. Goldstein
D. Borh

3: An atom has a mass number of 23
and atomic number 11. The number of protons
are_________.
A. 11
B. 12
C. 23
D. 44

4: The mass of the atom is determined
by________.
A. neutrons
B. neutron and proton
C. electron
D. electron and neutron

5: The K, L and M shells of an atom are
full. Its atomic number is_______.
A. 18
B. 20
C. 10
D. 12

6: Which of the air pressures is
appropriate for the production of cathode rays in
the discharge tube?
A. 1 cm Hg
B. 1 mm Hg
C. 0.001 cm Hg
D. 0.001 mm Hg

7: Cathode rays are deflected
towards__________.
A. positive electrode
B. negative electrode
C. both electrodes
D. none of the electrodes

8: The absolute charge of an electron
is___________.
A. - 1.6 x 10-19 C
B. + 1.6 x 10-19 C
C. 1.6 x 10-19 C
D. 16 x 10-19 C

9: The proton is heavier than an
electron by___________.
A. 1850 times
B. 1840 times
C. 1000 times
D. 100 times

10: Carbon-12 atom has_______________.
A. 6 electrons, 6 protons, 6 neutrons
B. 6 electrons, 12 protons, 6 neutrons
C. 12 electrons, 6 protons, 6 neutrons
D. 18 electrons, 6 protons and 6 neutrons

11: Chadwick got the Nobel Prize for the
discovery of __________.
A. protons
B. neutrons
C. electrons
D. mesons

12: Mass number is equal to
the_________.
A. number of protons + number of electrons
B. number of protons + number of neutrons
C. number of neutrons + number of electrons
D. number of electrons

13: The element X has 2 valence
electrons. It is a____________.
A. metal
B. non-metal
C. metalloid
D . gas

14: The volume of the nucleus of an
atom when compared to the extra nuclear part
is_________.
A. bigger
B. smaller
C. same size
D. unpredictable

15: In Rutherford's alpha-scattering
experiment, a foil of element that was used
_______________.
A. gold
B. silver
C. aluminum
D. magnesium

16: An element has an electronic
configuration of 2, 8, 7. Its valency is
A. 1
B. 7
C. 17
D. 8

17: The other name of H(1,1) is _________
A. protium
B. tritium
C. deuterium
D. proton

18: During a chemical reaction, atomic
number_________.
A. changes
B. remains same
C. changes and then is restored
D. changes alternately

19: The fixed circular paths around the
nucleus are called_________.
A. orbits
B. orbitals
C. nucleons
D. mesons

20. Almost the entire mass of an atom is
concentrated in the
1. protons.
2. electrons.
3. neutrons.
4. nucleus.

21. All ions of an element have the same
1. atomic number.
2. number of electrons.
3. number of protons.
4. both option A. and C.

22. The mass of the atom is determined by
1. proton.
2. electrons.
3. neutron and proton.
4. electron and proton.

23. The absolute charge of an electron is
1. - 1.6 × 10 -19 C.
2. + 1.6 × 10 -19 C.
3. 1.6 × 10 -19 C.
4. none of above

24. The fixed circular paths around the nucleus are
called
1. orbits.
2. orbitals.
3. mesons.
4. nucleus.

25. According to the Bohr model, an electron gains
or losses energy only by
1. moving faster or slower in an allowed orbit.
2. jumping from one allowed orbit to another.
3. being completely removed from an atom.
4. jumping from one atom to another atom.

26. The number of rings in the Bohr model of any
element is determined by what?
1. Column number on periodic table.
2. Atomic mass.
3. Row number on periodic table.
4. Atomic number.

27. How many valence electrons would be found in
an atom with the atomic number of 51?
1. 5.
2. 51.
3. 8.
4. none of above.

28. The Bohr model of the atom
1.
explained the color lines in the hydrogen
spectrum.
2.
could not explain the line spectrum of atoms
larger than hydrogen.
3.
had some made-up rules without explanations.
4. all of the above.

29. Maximum number of electrons in a sub-shell with
l = 3 and n = 4 is
1. 10.
2. 14.
3. 20.
4. 8.

30. Which of the following statements is not part of
Dalton's atomic theory?
1. All matter is composed of atoms.
2. Atoms can combine to form compounds.
3.
Atoms of different elements are quite different.
4. An atom contains a dense central nucleus.

31. Atoms with fewer than 4 valence electrons are
1. insulator.
2. semi-conductor.
3. conductor.
4. none of these.

32. Atoms have no electric charge because they
1.
have an equal number of charged and non
charged particles.
2. have neutrons in their nuclei.
3.
have an equal number of neutrons and protons.
4.
have an equal number of electrons and protons.

33. Two different isotopes of an element have
different
1. numbers of neutrons.
2. numbers of electrons.
3. atomic number.
4. numbers of protons.

34. What is the mass number of an element that has
19 protons, 19 electrons, and 20 neutrons?
1. 19.
2. 39.
3. 38.
4. 20.

35. Which of the following statements is not true?
1. A s orbital can hold two electrons.
2. A d orbital can hold ten electrons.
3. A f orbital can hold three electrons.
4. A p orbital can hold six electrons.

36. The drawback of Dalton's atomic structure is
that, it says
1.
the atoms can neither be created nor be
destroyed.
2. unique nature of atom.
3.
most of the volume of an atom is empty space.
4. none of these.

37. The electron configuration of copper is
1. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 8, 4s 1 4p 2.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 10, 4s 1.
3. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 9, 4s 2.
4. none of above.

38. Silicon has
1. four valence electrons.
2. eight valence electrons.
3. two valence electrons.
4. none of above.

39. The electron configuration of sulfur atom is
1. 2, 8, 6.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6.
3. 2, 8, 2.
4. none of these.

NB: These questions are from only one topic (section A) out of almost 6 or 7 topics as given by Geofavor. Pls let s attend to it urgently so that I can post more questions on other topics.

Nice one poster[/b]

OluchiDelly:

SECTION A

1: Almost the entire mass of an atom is
concentrated in the__________.

A. proton

B. electrons

C. nucleus

D. neutrons

2: Electron was discovered
by___________.
A. Chadwick
B. Thomson
C. Goldstein
D. Borh

3: An atom has a mass number of 23
and atomic number 11. The number of protons
are_________.
A. 11
B. 12
C. 23
D. 44

4: The mass of the atom is determined
by________.
A. neutrons
B. neutron and proton
C. electron
D. electron and neutron

5: The K, L and M shells of an atom are
full. Its atomic number is_______.
A. 18
B. 20
C. 10
D. 12

6: Which of the air pressures is
appropriate for the production of cathode rays in
the discharge tube?
A. 1 cm Hg
B. 1 mm Hg
C. 0.001 cm Hg
D. 0.001 mm Hg

7: Cathode rays are deflected
towards__________.
A. positive electrode
B. negative electrode
C. both electrodes
D. none of the electrodes

8: The absolute charge of an electron
is___________.
A. - 1.6 x 10-19 C
B. + 1.6 x 10-19 C
C. 1.6 x 10-19 C
D. 16 x 10-19 C

9: The proton is heavier than an
electron by___________.
A. 1850 times
B. 1840 times
C. 1000 times
D. 100 times

10: Carbon-12 atom has_______________.
A. 6 electrons, 6 protons, 6 neutrons
B. 6 electrons, 12 protons, 6 neutrons
C. 12 electrons, 6 protons, 6 neutrons
D. 18 electrons, 6 protons and 6 neutrons

11: Chadwick got the Nobel Prize for the
discovery of __________.
A. protons
B. neutrons
C. electrons
D. mesons

12: Mass number is equal to
the_________.
A. number of protons + number of electrons
B. number of protons + number of neutrons
C. number of neutrons + number of electrons
D. number of electrons

13: The element X has 2 valence
electrons. It is a____________.
A. metal
B. non-metal
C. metalloid
D . gas

14: The volume of the nucleus of an
atom when compared to the extra nuclear part
is_________.
A. bigger
B. smaller
C. same size
D. unpredictable

15: In Rutherford's alpha-scattering
experiment, a foil of element that was used
_______________.
A. gold
B. silver
C. aluminum
D. magnesium

16: An element has an electronic
configuration of 2, 8, 7. Its valency is
A. 1
B. 7
C. 17
D. 8

17: The other name of H(1,1) is _________
A. protium
B. tritium
C. deuterium
D. proton

18: During a chemical reaction, atomic
number_________.
A. changes
B. remains same
C. changes and then is restored
D. changes alternately

19: The fixed circular paths around the
nucleus are called_________.
A. orbits
B. orbitals
C. nucleons
D. mesons

20. Almost the entire mass of an atom is
concentrated in the
1. protons.
2. electrons.
3. neutrons.
4. nucleus.

21. All ions of an element have the same
1. atomic number.
2. number of electrons.
3. number of protons.
4. both option A. and C.

22. The mass of the atom is determined by
1. proton.
2. electrons.
3. neutron and proton.
4. electron and proton.

23. The absolute charge of an electron is
1. - 1.6 × 10 -19 C.
2. + 1.6 × 10 -19 C.
3. 1.6 × 10 -19 C.
4. none of above

24. The fixed circular paths around the nucleus are
called
1. orbits.
2. orbitals.
3. mesons.
4. nucleus.

25. According to the Bohr model, an electron gains
or losses energy only by
1. moving faster or slower in an allowed orbit.
2. jumping from one allowed orbit to another.
3. being completely removed from an atom.
4. jumping from one atom to another atom.

26. The number of rings in the Bohr model of any
element is determined by what?
1. Column number on periodic table.
2. Atomic mass.
3. Row number on periodic table.
4. Atomic number.

27. How many valence electrons would be found in
an atom with the atomic number of 51?
1. 5.
2. 51.
3. 8.
4. none of above.

28. The Bohr model of the atom
1.
explained the color lines in the hydrogen
spectrum.
2.
could not explain the line spectrum of atoms
larger than hydrogen.
3.
had some made-up rules without explanations.
4. all of the above.

29. Maximum number of electrons in a sub-shell with
l = 3 and n = 4 is
1. 10.
2. 14.
3. 20.
4. 8.

30. Which of the following statements is not part of
Dalton's atomic theory?
1. All matter is composed of atoms.
2. Atoms can combine to form compounds.
3.
Atoms of different elements are quite different.
4. An atom contains a dense central nucleus.

31. Atoms with fewer than 4 valence electrons are
1. insulator.
2. semi-conductor.
3. conductor.
4. none of these.

32. Atoms have no electric charge because they
1.
have an equal number of charged and non
charged particles.
2. have neutrons in their nuclei.
3.
have an equal number of neutrons and protons.
4.
have an equal number of electrons and protons.

33. Two different isotopes of an element have
different
1. numbers of neutrons.
2. numbers of electrons.
3. atomic number.
4. numbers of protons.

34. What is the mass number of an element that has
19 protons, 19 electrons, and 20 neutrons?
1. 19.
2. 39.
3. 38.
4. 20.

35. Which of the following statements is not true?
1. A s orbital can hold two electrons.
2. A d orbital can hold ten electrons.
3. A f orbital can hold three electrons.
4. A p orbital can hold six electrons.

36. The drawback of Dalton's atomic structure is
that, it says
1.
the atoms can neither be created nor be
destroyed.
2. unique nature of atom.
3.
most of the volume of an atom is empty space.
4. none of these.

37. The electron configuration of copper is
1. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 8, 4s 1 4p 2.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 10, 4s 1.
3. 1s 2 , 2s 2 2p 6, 3s 2 3p 6 3d 9, 4s 2.
4. none of above.

38. Silicon has
1. four valence electrons.
2. eight valence electrons.
3. two valence electrons.
4. none of above.

39. The electron configuration of sulfur atom is
1. 2, 8, 6.
2. 1s 2 , 2s 2 2p 6, 3s 2 3p 6.
3. 2, 8, 2.
4. none of these.

NB: These questions are from only one topic (section A) out of almost 6 or 7 topics as given by Geofavor. Pls let s attend to it urgently so that I can post more questions on other topics.

Nice one poster

Geofavor:
Icecalm, hope all is well?

yeah, I will be in on Sunday to take from A-E 20 questions

icecalm:
yeah, I will be in on Sunday to take from A-E 20 questions

alright, thanks.

To practice real time CBT on your smartphones, download prepa on playstore, blackberry appworld and window store(still in development). Visit prepaapp.com for more

Geofavor:
Oluchidelly, well done.

C. B. A. B. A. Don't know. A. C. B. A. B. B. A. B. C. A. C. B. B. D. 4: 3: 4: 2 :1 3: 4: 4: 1: 4: 3: 4: 1: 2: 3: 1: 4: 1: 1:

Good attempt.

damilola8775:
1:c,2:b,3:b,4:b,5:a,6:b,7:a,8:c,9:b,10:a,11:b,12:b,13:a,15:a,16:a,17:a,19:b,20:4,21:4,22:3,24:2,32:4,33:1,34:2,35:3,36:1,37:4,38:3,39:2....that's what I know sha

You try naun. I will post d answers soon. I am so sorry for posting d answers late.

Ans

1c
2b
3a
4b
5a
6d
7a
8a
9b
10a
11b
12b
13a
14b
15a
16a
17a
18b
19a
...
20.
Basically the nucleus is surrounded by
electrons. The nucleus contains protons
and neutrons, which are about 2000 times
more massive than the electrons outside
the nucleus. That is why most of the mass
of the atoms are concentrated in nucleus.

21.
Each of the ions of an element must have
same number of protons. Actually, an ion
may lose or gain the electrons further. Also
atomic number of an element is defined by
the number of protons present in the
nucleus of that element.

22.
The mass of the atom is the summation of
total mass of neutrons and protons. We do
not consider the electrons since the mass
of an electron is about 1 / 1800 times the
mass of a proton or neutron.

23. The electrons have always negative charge.
Thus, the absolute charge of an electron is
- 1.6 × 10 -19 C.

24.
We can call the circular path around the
sun as an orbit. Like that only, nucleus is
surrounded by electrons as circularly. That
is why we are calling that fixed circular
path as an orbit, too.

25.
As per Bohr model, the electrons can only
travel in special orbits at certain discrete
set of distances from the nucleus. It
does not lose energy while they travel.
They can only gain and lose energy by
jumping from one allowed orbit to another.

26.
Each electron shell can hold certain number
of electrons. For example,
Electron Shell --- No ofElectron
1 . - - - 2
2 - - - 8
3 - - - 8
4 - - - 18
5 - - - 18
6 - - - 32
7 - - - 32
As per this table, there were seven electron
shells which contain some number of
electrons. The orbit is nothing but rings.
The number of rings in the Bohr model of
any element is determined by row number
on periodic table.

27.
Antimony element has the atomic number
of 51. The valence electrons are referred
as the free electrons which are available at
the last orbit. In antimony, the total
electron shells are 5. They have the
following number of electrons with them.
First energy level : 2
Second energy level : 8
Third energy level : 18
Fourth energy level : 18
Fifth energy level : 5
Thus, the number of valance electron is 5.

28.
The Bohr model is a relatively primitive
model of the hydrogen atom, compared to
the valence shell atom. As a theory, it can
be derived as a first-order approximation of
the hydrogen atom using the broader and
much more accurate quantum mechanics.

29.
According to the Pauli's exclusion principle,
the maximum number of electrons in a
given sub-shell is 2( 2l + 1 ). Hence, 2( 2l
+ 1 ) = 2( ( 2 × 3) + 1 ) = 14. So, the
number of electrons in that sub-shell is 14.

30.
The Dalton’s atomic theory is not dealing
with dense central nucleus.

31.
Atoms with less than 4 valence electrons
will lose electrons to revert back to the
previous full energy level of electrons. This
happens in conductors only.

32.
Because, equal number of negative
electrons and positive protons would give a
result as neutral. That is why an atom does
not have electric charge.

33.
Two different isotopes have different
neutrons and they have same number of
protons. Thus, they have different mass
numbers. This means that they differ in the
number of neutrons but being the same
element.
34.
The mass number of an element is equal to
the addition of the number of protons and
neutrons.
35.
An atomic orbital is the concept used to
describe the behavior of electrons in the
atom. It is commonly used to determine
where an electron can be found as it
surrounds the nucleus of the atom. Each of
the four orbital holds a varied number of
electrons. The S orbital holds 2 electrons,
the P orbital holds 6 electrons, the D orbital
holds 10 electrons and the F orbital holds
14 electrons.

36.
The Dalton’s atomic theory deals with
chemical reactions. During chemical
reactions, an atom can neither be created
nor be destroyed. But, in radio active
reaction, new atoms can be created by
dividing other atoms. Thus, this is the very
big drawback of this method.

37.
Copper has totally 29 electrons. The
electron configuration is 2 + 8 + 18 + 1 =29
. We can write as 2 +(2 + 6) + (2 + 6 +
10) + 1.

38.
A semi conductor has 4 valence electrons.
Silicon is semi-conductor. So, the valence
electrons of Silicon are 4.

39.
1s 2 , 2s 2 2p 6, 3s 2 3p 4 is the electron
configuration of sulfur atom. Then 2, 8, 6
would match the 2 electrons in level 1, the
8 electrons in level 2 and the 6 electrons in
level 3.

Sorry guys, I didn't show up... I see you guys are doing good with oluchidelly and I still want to thank her and you guys for keeping the thread alive. I felt I should address Q (5). every shell has a maximum fixed amount of electrons it can accommodate and no element of the first twenty elements has it M shell completely filled with electrons. Elements with there M shell full with electrons would exist beyond the first twenty elements, tho, calcium has it shells electrons as 2,8,8,2 it doesn't imply that it M shell is full with electrons. To calculate the maximum electron on a full shell we use 2n², where n is a number assigned to each shell. The numbers are ordered in this form for each shells; K, L, M, N,... as 1, 2, 3, 4,...
Note the question does not state whether there is P, O or N shell in the atom but it state clearly that the M shell is full. I guess Q(5) was a typo.

(1) The charge of an electron was first measured by_____
(a) JJ Thompson
(b) Millikan
(c) John Dalton
(d) Rutherford

---

(2) A certain element X has four known isotopes with the following occurrence X⁵² 75.5%, X⁵⁵ 20%, X⁵⁷ 4% and X⁶¹ 0.5% in nature. Calculate the atomic mass of the element X
(a) 52.85g
(b) 53.50g
(c) 52.54g
(d) 51.96g

---

(3) The ionic radii of elements of the periodic table____
(a) increase across a period
(b) decrease across a period
(c) decrease down the group
(d) non of the above

---

(4) The most adoptable and yet incomplete periodic table was presented by____
(a) John Newlands
(b) Dmitri Mendeleev
(c) John Dalton
(d) Raoult

---

(5) The ionization energy of elements of the periodic table___
(a) decrease across a period
(b) increase across a period
(c) increase down a group
(d) non of the above

---

(6) group 7 elements have the following properties except___
(a) there boiling point increase down the group
(b) there reactivity increase down the group
(c) there reactivity decrease down the group
(d) non of the above

---

(7) An example of electrovalent bond exist in____
(a) NH₄⁺
(b) NaCl
(c) HCl
(d) H₂O

---

(8. ) Water has an exceptional boiling point compared to other compounds of comparable molecular mass due to___
(a) It atomic resonance
(b) it strong covalent bonds
(c) it hydrogen bonds
(d) it hydraulic action

---

(9) The special type of bond in ammonium ion is____
(a) Hydrogen bond
(b) Covalent bond
(c) Coordinate bond
(d) Ionic bond

---

(10) From the periodic table metallic properties increase___
(a) across the period
(b) down the group
(c) both a and b
(d) non of the above

---

from A-C
geoflavor, debbyChris, Mheesa and others

icecalm:
.... I felt I should address Q (5).... no element of the first twenty elements has it M shell completely filled with electrons. Elements with there M shell full with electrons would exist beyond the first twenty elements, tho, calcium has it shells electrons as 2,8,8,2 it doesn't imply that it M shell is full with electrons. To calculate the maximum electron on a full shell we use 2n², where n is a number assigned to each shell. The numbers are ordered in this form for each shells; K, L, M, N,... as 1, 2, 3, 4,...
Note the question does not state whether there is P, O or N shell in the atom but it state clearly that the M shell is full. I guess Q(5) was a typo.

It takes a genius to spot that technical error. Thank you.
What icecalm was saying in essence is M shell contains 3 orbitals(s, p, d).
And S can contain max of 2electrons, p... 6 electrons, d.... 10 electrons. Total =18 electrons.
Only elements beyond Ca in the p/table use the d-orbital. For element like Ca without the d-electron, Max no of electrons on its M-shell =8(2 from S, and 6 from P).
According to the question, an atom with a FULLY filled K-shell(=2e) , L-shell (=8e) , M-shell(=18e) . Total=2+8+18=28 electrons.
The correct ans is 28. But 28 is not among the options.
Once again thank you for the observation.

DOCTORPRESH:
Hello everyone,
I don't mean to derail this thread, but I just wanna ask my fellow Nigerian students something which might be a little off the topic of discussion on this thread: Do you all jot, I mean take notes while reading/studying? Personally, I don't. And sometimes I feel its just sheer laziness, how does taking notes affect comprehension and retention? Sometimes I just try to do it but it really slows my reading pace.
Your opinions will be highly appreciated.

In other disciplines, jotting might not be necessary. But in science, especially chemistry, how would you assess yourself after reading if you did not jot down some points/questions.?
Let's say you read a topic like radioactivity. These are the questions you need to ask your self after reading:
What is fission,..... Fusion, difference between..., properties of alpha, beta, gamma particles,.... Comparisons between alpha, beta, gamma, etc. The best way to go about it is by jotting.
If you claim to have read and you didn't ask/examine yourself (on what you read) , then you have not studied.

OluchiDelly:


In other disciplines, jotting might not be necessary. But in science, especially chemistry, how would you assess yourself after reading if you did not jot down some points/questions.?
Let's say you read a topic like radioactivity. These are the questions you need to ask your self after reading:
What is fission,..... Fusion, difference between..., properties of alpha, beta, gamma particles,.... Comparisons between alpha, beta, gamma, etc. The best way to go about it is by jotting.
If you claim to have read and you didn't ask/examine yourself (on what you read) , then you have not studied.

I usually use the study questions at the end of each topic without necessarily writing anything.. I just do it all in my head, except I need to solve... But I'm trying to make a productive revolution in my study pattern for best results, hence my silly question..
Thanks for your answer... I'ld just try to do it.

DOCTORPRESH:
I usually use the study questions at the end of each topic without necessarily writing anything.. I just do it all in my head, except I need to solve... But I'm trying to make a productive revolution in my study pattern for best results, hence my silly question..
Thanks for your answer... I'ld just try to do it.

it wasn't

Geofavor:
it wasn't

Thank you.

icecalm:
(1) The charge of an electron was first measured by_____
(a) JJ Thompson
(b) Millikan
(c) John Dalton
(d) Rutherford

---

(2) A certain element X has four known isotopes with the following occurrence X⁵² 75.5%, X⁵⁵ 20%, X⁵⁷ 4% and X⁶¹ 0.5% in nature. Calculate the atomic mass of the element X
(a) 52.85g
(b) 53.50g
(c) 52.54g
(d) 51.96g

---

(3) The ionic radii of elements of the periodic table____
(a) increase across a period
(b) decrease across a period
(c) decrease down the group
(d) non of the above[/b]

---

(4) The most adoptable and yet incomplete periodic table was presented by____
(a) John Newlands
(b) Dmitri Mendeleev
(c) John Dalton
(d) Raoult

---

(5) The ionization energy of elements of the periodic table___
(a) decrease across a period
(b) increase across a period
(c) increase down a group
(d) non of the above

---

(6) group 7 elements have the following properties except___
(a) there boiling point increase down the group
(b) there reactivity increase down the group
(c) there reactivity decrease down the group
(d) non of the above

---

(7) An example of electrovalent bond exist in____
(a) NH₄⁺
(b) NaCl
(c) HCl
(d) H₂O

---

(8. ) Water has an exceptional boiling point compared to other compounds of comparable molecular mass due to___
(a) It atomic resonance
(b) it strong covalent bonds
(c) it hydrogen bonds
(d) it hydraulic action

---

(9) The special type of bond in ammonium ion is____
(a) Hydrogen bond
(b) Covalent bond
(c) Coordinate bond
(d) Ionic bond

---

(10) From the periodic table metallic properties increase___
(a) across the period
(b) down the group
(c) both a and b
(d) non of the above

---

from A-C
geoflavor, debbyChris, Mheesa and others

next ....

Geofavor:

next ....

I didn't check the rest o, but the number 9, I think it's rather coordinate covalent (Dative) bond