I hope am not too late...Lemme join

seuntosyn:
how i can i go from total chemistry dullard to become very
good in chemistry in 3months .
PLEASE
I need details and not story or affront

Learning is a gradual process, 3 months too short for chemistry.

Geofavor:
If 12 and 9 are the atomic numbers of elements A and B respectively, the interatomic bond between these elements is

a) co-ordinate b) neutral c) covalent d) ionic

cc icecalm, oluchidelly, mathfaro. pls help me answer this with a good explanation. Thanks

First, write out their electronic configurations to deduce their groups in periodic table.

A=12=2, 8, 2=group 2, i.e a metal, an electropositive element /atom.

B=9= 2, 7=group 7, halogen group i.e electronegative atom.

Ans=ionic or electrovalent bond, I. e, a bond between electro+ve atom and electro-ve atom

OluchiDelly:


First, write out their electronic configurations to deduce their groups in periodic table.

A=12=2, 8, 2=group 2, i.e a metal, an electropositive element /atom.

B=9= 2, 7=group 7, halogen group i.e electronegative atom.

Ans=ionic or electrovalent bond, I. e, a bond between electro+ve atom and electro-ve atom

thanks ma'am. But how will they bond with eachother ionically(electron transfer) I mean, A has just 1 valence electron, B has just 2. In my own understanding, if this metal atom transfers (or even share) its valence electrons to the halogen, the halogen wouldn't still have a complete outermost shell. Does this mean they can still combine irrespective of this?

Geofavor:

thanks ma'am. But how will they bond with eachother ionically(electron transfer) I mean, A has just 1 valence electron, B has just 2. In my own understanding, if this metal atom transfers (or even share) its valence electrons to the halogen, the halogen wouldn't still have a complete outermost shell. Does this mean they can still combine irrespective of this?

One atom of A will bond with two atoms of B. i. e, A will transfer each of its two electrons to each of the 2 atoms of B. Examples are: MgF2, CaCl2, MgCl2,.
In this case, the real compound formed is MgF2.
F...Mg...F

Geofavor:

thanks ma'am. But how will they bond with eachother ionically(electron transfer) I mean, A has just 1 valence electron, B has just 2. In my own understanding, if this metal atom transfers (or even share) its valence electrons to the halogen, the halogen wouldn't still have a complete outermost shell. Does this mean they can still combine irrespective of this?

The valence electron of A is not 1 and that of B too is not 2. Don't confuse lone pair electron, unpaired electron, valence electron with one another.
1. Elements are grouped in d periodic table based on the no of electron on the outermost shell. E.g, Fluorine has 7e on d outermost shell, so it belongs to group 7, that does not mean it's valence is 7.
2.valence or valency is the no of electron an atom can lose(for metal/electropositive atom) or gain(for non metal /electro-ve atom) for a bonding to take place. i.e d combining power of that atom.
3.in ur question, d valency of A is 2, and B is - 1 (d minus sign shows it will accept 1e to complete its octet and becomes - vely charge, that is d difference between it and group one elements with valency of +1)
I am a man, feel free to ask any question wherever you feel, I will try to ans you to the best of my ability.

OluchiDelly:

One atom of A will bond with two atoms of B. i. e, A will transfer each of its two electrons to each of the 2 atoms of B. Examples are: MgF2, CaCl2, MgCl2,.
In this case, the real compound formed is MgF2.
F...Mg...F

and justice has been done to my questions. Thank you sir

OluchiDelly:

The valence electron of A is not 1 and that of B too is not 2. Don't confuse lone pair electron, unpaired electron, valence electron with one another.
1. Elements are grouped in d periodic table based on the no of electron on the outermost shell. E.g, Fluorine has 7e on d outermost shell, so it belongs to group 7, that does not mean it's valence is 7.
2.valence electron or valency is the no of electron an atom can lose(for metal/electropositive atom) or gain(for non metal /electro-ve atom) for a bonding to take place. i.e d combining power of that atom.
3.in ur question, d valency of A is 2, and B is - 1 (d minus sign shows it will accept 1e to complete its octet and becomes - vely charge, that is d difference between it and group one elements with valency of +1)
I am a man, feel free to ask any question wherever you feel, I will try to ans you to the best of my ability.

thanks. Ahh, I have a lot of questions o.

OluchiDelly:

The valence electron of A is not 1 and that of B too is not 2. Don't confuse lone pair electron, unpaired electron, valence electron with one another.
1. Elements are grouped in d periodic table based on the no of electron on the outermost shell. E.g, Fluorine has 7e on d outermost shell, so it belongs to group 7, that does not mean it's valence is 7.
2.valence electron or valency is the no of electron an atom can lose(for metal/electropositive atom) or gain(for non metal /electro-ve atom) for a bonding to take place. i.e d combining power of that atom.
3.in ur question, d valency of A is 2, and B is - 1 (d minus sign shows it will accept 1e to complete its octet and becomes - vely charge, that is d difference between it and group one elements with valency of +1)
I am a man, feel free to ask any question wherever you feel, I will try to ans you to the best of my ability.

[email] I'm confused. Please, differentiate between valency and valence electron with examples. 'cause I was taught that valence electron is the electron on the outermost shell. [/email]

Tobiee:
[email] I'm confused. Please, differentiate between valency and valence electron with examples. 'cause I was taught that valence electron is the electron on the outermost shell. [/email]

Sorry for the confusion. Your own definition of "valence electron" Is right. My definition and explanation u quoted above is of "valence" or "valency". Both valence and valency mean same thing. For better clarification, pls read a soft copy of a chemical encyclopedia I copied n pasted below.... (that is the more reason I get my self acquainted with this thread to refresh my memory by also learning from you younger generation).

............
by The Editors of Encyclopædia
Britannica
Last Updated 1-4-2016
... shells don't stack neatly one on top of another, so don't always assume an element's valence is determined by the number of electrons in its outer shell.

Valence describes how easily an atom or
radical can combine with other chemical
species. This is determined based on the
number of electrons that would be added,
lost or share if it reacts with other atoms.

Valence is denoted using a positive or
negative integer used to represent this
binding capacity. For example, common
valences of copper are 1 and 2.


Element /Valence
1 Hydrogen (-1), +1
2 Helium 0
3 Lithium +1
4 Beryllium +2
5 Boron -3, +3
6 Carbon (+2), +4
7 Nitrogen -3, -2, -1, (+1), +2, +3,
+4, +5
8 Oxygen -2
9 Fluorine -1, (+1)
10 Neon 0
11 Sodium +1
12 Magnesium +2
13 Aluminum +3
14 Silicon -4, (+2), +4
15 Phosphorus -3, +1, +3, +5
16 Sulfur -2, +2, +4, +6
17 Chlorine -1, +1, (+2), +3, (+4), +5,
+7
18 Argon 0
19 Potassium +1
20 Calcium +2

@tobie,
You can see from the table, that element like Oxygen has "valence / valency" of -2 (but has "valence electrons" of 6, i. e 6 electrons on the outermost shell)
Same thing applicable to He, Ne with 0 valences.

Icecalm are you on sabbatical? You ve been too quite o.

OluchiDelly:
Icecalm are you on sabbatical? You ve been too quite o.

I'm seriously occupied at this moment but I urge the chemistry jambites of this thread to put more effort in their studies and try to come to the thread to ask questions on topics they don't really understand or even questions they find difficult to solve. I will be of help if I get their mentions. Geofavor please pick random topics, the salient topics should be of choice, so that clarification could be made on one or two things on it.

*heaves a sigh*

lemme say hi.

I so much love chemistry!

pls can anybody shed more light on the quantum numbers of an atom

pls can anybody shed more light on the quantum numbers of an atom. kos its really giving me headache

I would like to be a student in dis thread. Am I welcum?

OluchiDelly:
@tobie,
You can see from the table, that element like Oxygen has "valence / valency" of -2 (but has "valence electrons" of 6, i. e 6 electrons on the outermost shell)
Same thing applicable to He, Ne with 0 valences.

. Oxygen needs only 2 electrons to form octet structure.

Tobiee:
[email] I'm confused. Please, differentiate between valency and valence electron with examples. 'cause I was taught that valence electron is the electron on the outermost shell. [/email]

Valency is d combining power of an element while valence electron is d number of electron in d outermost layer of an element

Veronica0705:
pls can anybody shed more light on the quantum numbers of an atom. kos its really giving me headache

hi

what exactly about them is giving you problems? What don't you know about them?

goodygallant:
I would like to be a student in dis thread. Am I welcum?

you're extremely welcome

OluchiDelly:
Icecalm are you on sabbatical? You ve been too quite o.

[email] Thanks sir. Hope to learn more from this thread. BTW can you please talk on periodic table?

Thanks. [/email]

Tobiee:
[email] Thanks sir. Hope to learn more from this thread. BTW can you please talk on periodic table?

Thanks. [/email]

FYA icecalm

Veronica0705:
pls can anybody shed more light on the quantum numbers of an atom. kos its really giving me headache

.

Quantum numbers QN are nos which describe electron(s) with respect to its atomic orbital /shell.
There are 4 of them:
Principal quantum number (PQN)
azimuthal or subsidiary quantum number AQN
magnetic Quantum number MQN
spin quantum number SQN

I will be talking on each in segments so as not to be too boring while reading. Watch out for the next segment.

OluchiDelly:

FYA icecalm

here I am, what's the call for.

icecalm:
here I am, what's the call for.

Attend to @tobiee. WRT periodicTable

Principal Quantum number. It is represented by n. These numbers describe the energy levels or atomic shells where electron can be found. They(shells) are numbered outward or away from the nucleus. The PQ numbers i. e, n are 1,2,3,4...
When PQN (n) is 1, it implies K-shell.
,, ,, 2 ,, ,, L-shell.
,, ,, 3 ,, ,, M-shell
,, ,, 4 ,, ,, N-shell.

The total/max no electron that can be found on each energy level is given by 2n². Where n=PQN.
so if n=3 (3rd energy level), Max no of electrons will be 2*3²=18.

2. azimuthal quantum no. It is denoted by i. It describes the NUMBER /TYPE/SHAPE OF ORBITAL that can be found in a given energy level(PQN). i ranges from 0,1,2,3...
0 implies s-orbital, shape=spherical
1 implies p-orbital, shape=dumbbell
2 implies d-orbital, shape=double dumbbell
3 implies f-orbital....

This is how the numbers are arrived at.

The formula is i=n-1(write out your answer from zero, since it ranges from 0).

If n=1(K-shell), i=1-1=0, meaning that on K-shell, you have only one orbital which is S-orbital(since zero stands for s-orbital)

If n=2, i=n-1,then i=2-1=1..... (0,1) (remember, count out your answer from zero) Then count the digits, no of digits=no of orbitals. There are two digits(0,1) meaning there are two orbitals in L-shell (S and P).

Let's apply this principle for 3rd energy level

If n=3, i=n-1, 3-1=2....(0,1,2) meaning there are 3 types of orbitals in M-shell.
0 stands for S
1 stands for p
2 stands for d

Pls, try work out on a sheet of paper the number/type of orbitals (i.e the azimuthal quantum number) on N-shell based on this explanation.


I will take a pause here to entertain your questions before I proceed.

Tobiee:
[email] Thanks sir. Hope to learn more from this thread. BTW can you please talk on periodic table?

Thanks. [/email]

The periodic table is a systematic arrangement of elements in periodic manner in which the position of each element in the periodic table defined by it atomic number describes the chemical properties of the element. In other word, the periodic table is a periodic function of the properties of the elements. Some properties of elements on the table tend to be similar, this in turn help us to divide the elements of the table into groups. generally, the chemistry of each group is treated to be specific. And when we move from group 1 to group 2 along a row, we have moved across a period.

Remark: we don't say, move across groups when reading a periodic table, we only move down a group.

Properties of elements of the periodic table can be predicted if one have an idea of the properties of the group they belong. This properties include valency, reactivity and others, but however, this similar properties tend to vary as we move down the groups. For instance all group 1 elements are metals of valence 1+ except H, but there reactivity varies down the group. This is similar for other groups but the pattern in which this properties varies is in two was, it's either it decreases or increases down the group. This patterns is also true for describing movement across periods. Now, let us describe some properties of the periodic table and how they varies.

This variations is general of the entire table.
*Metallic properties decrease across periods.
Using period 2 as reference we find out that metallic properties decrease in the order: Li>Be>B>C>N>O>F>Ne.
With Neon being an inert gas. This inert property is true for elements of that group but xenon is radioactive.
**Metallic properties increase down the group. When you hear metal, I suppose by now you shouldn't be thinking of something hard always as some metals are very soft and even liquid in state e.g mercury (Hg). Some properties of metals are defined with regard to there ability to donate electrons, this could be accounted for the reason Hydrogen was place in group 1 elements. When we move down the group we found out that the ability of the elements to donate electrons will increase and hence the energy required to activate the release of their valence electrons (electrons they can donate) will be lower. For instance, when we dissolve 1mol of potassium in 1litre of water and do same for Lithium, it's obvious that water that contain potassium will have the content of potassium reacted quickly compare to the one with Lithium. This is due to the fact that potassium loss it valence electrons to H⁺ more easily compare to Lithium. The rate at which each content may react can be made equal if heat is supplied to the water containing Lithium. Some metals do
not react in water at room temperature at all. From this concept,it follows that the most reactive metal in group 1 is caesium.
***The ironic radii/atomic radii of elements increased down the group and decrease across periods.
This could be accounted for the reason elements of group 7 tend to be more electronegative than there companion, group 6. This is because the electrons in large number are close to the nucleus and the electrostatic force of attraction between positive and negative electrons is also high and make it difficult for the elements to donate electrons under normal conditions.
**** Ionization energy increase across periods and decrease down the group. Ionization energy is the energy required to remove the most loosely bound electron from it shell in order to make the elements becomes positively charge.

Preposition: Electronegative increase across periods and decrease down the group.
Remark: If we define property * and ** with respect to nonmetallic properties the result however will be otherwise for instance; nonmetallic properties increase across periods and decrease down the group.

I will continue when next I come online. This post is only meant to explain the general properties of the periodic table.