Periodicity

Question 1

How are the elements arranged in the periodic table?

Answer 1

They are arranged in the order of increasing atomic number

Question 2

What is a period on the periodic table?

Answer 2

The horizontal rows

Question 3

What is a group on the periodic table?

Answer 3

The vertical columns

Question 4

What’s is meant by periodicity?

Answer 4

The repeating trends in chemical and physical properties

Question 5

What change happens across each period?

Answer 5

Element change from metals to non metals

Question 6

How can the electron configuration be written in short?

Answer 6

The noble gas before the element is used to abbreviate

Question 7

Define first ionisation energy?

Answer 7

The energy required to move one electron from each atom in one mole of the gaseous element to form one mole of gaseous ion 1+

Question 8

Write an equation for the first ionisation energy of magnesium?

Answer 8

Mg (g) — Mg+(g) + e-

Question 9

What are the factors that affect ionisation energy?

Answer 9

Atomic radius, nuclear charge, electron shielding

Question 10

Why does first ionisation energy decrease between group 2 to 3?

Answer 10

Decrease between 2 to 3 because in group 3 the outermost electrons are in p orbital whereas in group 2 they are in s orbital, so the electrons are easier to remove

Question 11

Why does first ionisation energy decrease between group 5 to 6?

Answer 11

The decrease between 5 to 6 is due to the group 5 electrons in p orbital are single electrons and in group 6 the outermost electrons are spin paired with some repulsion. Therefore the electrons are slightly easier to remove.

Question 12

Does first ionisation increase or decrease between the end of one period and the start of the next? Why?

Answer 12

Decrease
- there is increase in atomic radius
- increase in electron shielding

Question 13

Does first ionisation increase or decrease down a group? Why?

Answer 13

Decrease
Shielding increases - weaker attraction
Atomic radius increases - distance between the outer electron and the nucleus increases - weaker attraction
Increase in number of protons is outweighed by increase in distancing and shielding

Question 14

What are the properties of giant metallic lattice?

Answer 14

High melting and boiling points
Good electrical conductivity
Malleability
Ductility

Question 15

What is a ductile metal?

Answer 15

The metal can be made stretched

Question 16

What is a malleable metal?

Answer 16

This metal can be shaped into different forms

Question 17

Describe the structure, forces and bonding in every element across period 2

Answer 17

-Li and Be — giant metallic; strong attraction between positive ions and delocalised electrons; metallic bonding
-B and C — giant covalent; strong forces between atoms; covalent
-N2,O2,F2,Ne — simple molecular; weak intermolecular forces between molecules; covalent bonding within molecules and intermolecular forces between molecules

Question 18

Describe the structure, forces and bonding in every element across period 3

Answer 18

• Na,Mg,Al — giant metallic; strong attraction between positive ions and delocalised electrons; metallic bonding
  -Si — giant covalent; strong forces between atoms; covalent
  -P4,S8,Cl2,Ar — simple molecular; weak intermolecular forces between molecules; Co vale t bonding within molecules and intermolecular forces between molecules