Periodicity

Question 1

What is the definition of periodicity

Answer 1

Repeating trends in chemical and physical properties of an element

Question 2

What does the electronic configuration decide

Answer 2

Decides the chemical properties of an element

Question 3

What do s block elements form when they lose an electron

Answer 3

Forms positive ions with an inner gas configuration

Question 4

What do p block element form when they gain electrons

Answer 4

Form negative ions with an inert gas configuration

Question 5

What do D block elements tend to lose

Answer 5

S and d electrons to form positive ion

Question 6

How does the atomic radius decrease across a period

Answer 6

The nuclear charge increases so the positive charge of the nucleus increases
This means electrons are pulled closer to the nucleus which makes the atomic radius smaller

Question 7

Why doesn’t the extra electrons added to the outer shell electron affect shielding

Answer 7

Shielding occurs with inner electrons not outer shell electrons so extra shielding isn’t experienced

Question 8

Why does ionisation energy increase ad you move across a period

Answer 8

There is a stronger nuclear attraction because of increase number of protons
The extra electrons are in roughly the same energy levels which means there is no extra shielding effect or extra distance to lessen the attraction from the nucleus

Question 9

What do the drops in group 2 and 3 show

Answer 9

Subshell structure

Question 10

More energy is required to remove an electrons from …

Answer 10

A higher energy level than a lower energy level

Question 11

Why is there a drop in ionisation energy for aluminium

Answer 11

-Aluminiums outer electron is in the 3p orbital which has a slightly higher energy than 3s orbital so the electron is further away from the nucleus
-3p orbital experiences additional shielding which is provided by the 3s2 electrons
-These factors override effect of increased nuclear charge which results in ionisation energy dropping

Question 12

What are the drops in group 5 and 6 due to

Answer 12

Electron repulsion

Question 13

Which element are stable and have higher ionisation energies

Answer 13

Elements with singly filled or full Subshell are more stable than those with partially filled sub shells so they have higher ionisation energies

Question 14

Why does phosphorus have a higher ionisation energy than sulfur

Answer 14

Phosphorus has a single occupied orbital whereas sulfur has the electron is being removed from an orbital containing two electrons

Question 15

What is the shielding like in phosphorus and sulfur atoms

Answer 15

The shielding is identical and the electron being removed is from an identical orbital

Question 16

Why is having two electrons in an orbital mean the ionisation energy decreases

Answer 16

There is repulsion from the two electrons in an orbital making it easier to remove so less energy is required to remove the electron from the orbital

Question 17

What happens across period 2 melting and boiling point as you go across the period

Answer 17

The melting and boiling point increases because the metallic bonds get stronger as the metal ions have increasing number of delocalised electrons and a decreasing atomic radius
This means there’s a stronger attraction between metal ions and delocalised electrons so a stronger metallic bond

Question 18

What happens to the melting and boiling point of elements with a giant covalent lattice

Answer 18

-there is a string covalent bond which links the atoms together
-this means a lot of energy is required to break all of these bonds

Question 19

Which elements with a giant covalent lattice have high boiling points

Answer 19

Silicone and carbon

Question 20

What is the boiling points like in simple molecular structures

Answer 20

-Melting points depend on London forces which are weak and easy to overcome so the melting point is low

Question 21

How can simple molecular structures have a high boiling point and give an example of an element with a high melting point

Answer 21

More electrons which mean the London forces are stronger
Sulfur