Task 1. Glossary

an atom. Sometimes called the proton number.
electron arrangement – A

shorthand way of writing the number of electrons in an atom’s electron shells.
element – A substance made up of only one type of atom.
group – A column in the periodic table
period – A row in the periodic table containing elements with the same number of full electron shells.
periodic table – A table that lists all the elements in order of increasing atomic number
property – Any characteristic of an element.

periodicity
pattern
outermost
shell, subshell
valence electron
arrange, arrangement
consider
increase
distribute
belong

Make your own glossary

periodicity.
What is the periodicity?

the the repetition of outermost shell electrons after certain regular

intervals.

2, 1

2, 8, 1

Na

2, 8, 8, 1

K

For example:
All the elements of group IA (alkali metals) end with the similar number of valence electrons which is ONE.
Because of similarity in the electronic configuration of all the elements in a same group have similar properties.

1А GROUP
ALKALI METALS

the number and arrangement of electrons in the atom.
As atomic

number increases by one, the number of electrons also increases by one.
This means that the elements in the periodic table are also arranged in order of the number of electrons.

atomic number = number of protons
number of protons = number of electrons
atomic number = number of electrons

This electron arrangement is written as 2,8,8
Each shell has

a maximum number of electrons that it can hold.
Electrons will fill the shells nearest the nucleus first.

only have electrons in the first shell.
Why are there only

two elements in period 1?

The first shell can only hold a maximum of two electrons,
so period 1 only includes the elements hydrogen and helium.

What is special about the outer shell of helium?

1

2

1

2

4

3

5

6

8

7

second shell the number of electron increases by one electron

across the period from left to right.
What is special about the outer shell of neon?

2,1

2,2

2,3

2,4

2,5

2,6

2,7

2,8

1

2

4

3

5

6

8

7

What happens to electrons in the second shell in period 2?

Electrons in period 2

happens to electrons in the third shell in period 3?

Аt

second shell the number of electron increases by one electron across the period from left to right.

Na

Mg

Al

Si

P

S

Cl

Ar

1

2

4

3

5

6

8

7

Electrons in period 3

20 elements in the periodic table.
What is the pattern of

outer shell electrons in a group?

What is the pattern of outer shell electrons across a period?

What is the pattern of full electron shells in a group?

start of new period electrons begin to fill a new

shell.

The number of a group is the same as the number of electrons in the outer shell of elements in that group.

the number of complete electron shells increases by one;

the number of outer shell electrons is the same.

the number of outer shell electrons increases by one;

the number of complete electron shells stays the same.

Trends across a period:

is the same as the number of electrons in the

outer shell of elements in that group.

The number of period is the same as the number of electron shells

and subshells. The arrangement of electrons can be shown by

electronic configuration.

The physical and chemical properties of elements can be explained by their unique electron configuration.

The electron configuration simply the order of shells and subshell. In other word it is called orbitals. There are s, p , d and f orbitals.

s d p s d

p s f d p s f d p s

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s d p s d

p s f d p s f d p s

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p 5s d p 6s f

d p 7s f d p 8s

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

5s2 d p 6s2 f d p

7s2 f d p 8s2

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2st shell and it can only contain maximum 6 electrons.

5p 6s2 f d 6p 7s2 f d

7p 8s2

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2st shell and it can only contain maximum 6 electrons.

5p6 6s2 f d 6p6 7s2 f d

7p6 8s2

THE WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

5p6 6s2 f 5d 6p6 7s2 f 6d 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

5p6 6s2 f 5d10 6p6 7s2 f 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

f-orbital starts from 4th shell and it can only contain maximum 14 electrons.

5p6 6s2 4f 5d10 6p6 7s2 5f 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

f-orbital starts from 4th shell and it can only contain maximum 14 electrons.

5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

f-orbital starts from 4th shell and it can only contain maximum 14 electrons.

5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

s-orbital starts from 1st shell and it can only contain maximum 2 electrons.

p-orbital starts from 2nd shell and it can only contain maximum 6 electrons.

d-orbital starts from 3rd shell and it can only contain maximum 10 electrons.

f-orbital starts from 4th shell and it can only contain maximum 14 electrons.

5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

Example:

Write the electronic configurations of the following elements

Li3, B5, Mg12, S16

Li3

1s2 2s1

B5

1s2 2s2 2p1

Al13

1s2 2s2 2p6 3s2 3p1

Ar18

1s2 2s2 2p6 3s2 3p6

5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

Example:

Write the electronic configurations of the following elements

Li3, B5, Mg12, S16

Li3

1s2 2s1

B5

1s2 2s2 2p1

Al13

1s2 2s2 2p6 3s2 3p1

Ar18

1s2 2s2 2p6 3s2 3p6

number of shells is 2, so it is in 2nd period, valence electron is 1, so 1A group

shells are 2 >>> 2nd period, valence electrons are 3, so 3A group

shells are 3 >>> 3nd period, valence electrons are 3, so 3A group

shells are 3 >>> 3nd period, valence electrons are 8, so 8A group

5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6 8s2
THE

WAY OF THE FILLING THE ELECTRONIC CONFIGURATION

Al13

1s2 2s2 2p6 3s2 3p1

Fe26

1s2 2s2 2p6 3s2 3p6 4s2 3d10

Elements with ending s and p orbitals in their electronic configurations belong to A group

Elements with ending d and f orbitals in their electronic configurations belong to B group

classified as s-block, p-block, d-block and f-block.
OR
s-elements, p-elements, d-elements and

f-elements

1A and 2A group elements belong to s-blocks

3A-8A group elements belong to p-blocks

Elements of Actinides and Lanthanides belong to f-blocks

transition metals belong to d-blocks

words and share your answer with the class.

of chemical properties

periodicity A repeating pattern is called in elements
end with which is ONE of group IA valence electrons number of (alkali metals) All the elements the similar
of electrons neutral atoms and the number are same of protons the number For the
in the of electrons. periodic table the number are also The elements arranged in order of

called periodicity.
All the elements of group IA (alkali metals) end

with the similar number of valence electrons which is ONE.
For the neutral atoms the number of protons and the number of electrons are same.
The elements in the periodic table are also arranged in order of the number of electrons.

sentences 2 words are changed their places. Find the words

and replace them in a best way.

Electrons are arranged in the nucleus around an atom’s shell.
__________________________________________________________________
The number of electron is the same as the number of period shells.
__________________________________________________________________
The physical and chemical configuration of elements can be explained by their unique electron properties.
__________________________________________________________________
Second electron number can only hold maximum eight shell of electrons.
__________________________________________________________________

sentences 2 words are changed their places. Find the words

and replace them in a best way.

Electrons are arranged in the shell around an atom’s nucleus.
The number of period is the same as the number of electron shells.
The physical and chemical properties of elements can be explained by their unique electron configuration.
Second electron shell can only hold maximum eight number of electrons.

sentences and make best matching of words from 4 columns.

______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________

sentences and make best matching of words from 4 columns.

In

a group, from top to bottom the number of complete electron shells increases by one
In a group, from top to bottom the number of valence electrons stays the same
In a period, from left to right the number of complete electron shells stays the same
In a period, from left to right the number of valence electrons increases by one

elements and indicate the location of the element by group

and period.
Be4, N7, Si14, Zn30

Be4
1s2 2s2 number of shells is 2, so it is in 2nd period, valence electron is 2, so 2A group

N7 __________________________________________________________________
Si14 _________________________________________________________________
Zn30 ________________________________________________________________