Module 2 Teacher 1

Question 1

How many electrons can fill a shell?

Answer 1

This can be found by using 2n^2. Therefore for the first four shells:
1:2
2:8
3:18
4:32

Question 2

What are atomic orbitals?

Answer 2

A region around the nucleus that can hold up to two electrons with opposite spins.

Question 3

What shape is the s orbital?

Answer 3

Sphere shaped (O)

Question 4

What shape is the p orbital?

Answer 4

Dung bell shaped (8)

Question 5

How many orbitals and electrons are in s-, p-, and d-sub shells?

Answer 5

s: 1 orbital so two electrons
p: 3 orbitals so six electrons
d: 5 orbitals so 10 electrons

Question 6

What is the filling order of orbitals?

Answer 6

4s fills before 3d except in in:
Cu = [Ar] 3d^10 4s^1
Cr = [Ar] 3d^5 4s^1

Question 7

How do electrons occupy orbitals of the same energy level?

Answer 7

Singly before pairing as they are all negatively charged so will repel one another.

Question 8

How is the periodic table classified into blocks?

Answer 8

Group 1-2 is the s-block.
Group 3-12 is the d-block.
Group 13-18 is the p block.

Question 9

Definition of first ionisation energy:

Answer 9

The energy needed to remove 1 mol of electrons from 1 mol of gaseous atoms to give 1 mol of positively charged 1+ ions.

Question 10

A formula to show ionisations:

Answer 10

H (g) —> H+ (g) + e-

Question 11

What factors affect ionisation energy?

Answer 11

-atomic radius: the greater the atomic radius the smaller the nuclear attraction experienced on outer shell electrons.
-nuclear charge: the greater the nuclear charge the greater the attractive force experienced on outer shell electrons.
-electron shielding: this is the repulsion between electrons in different inner shells. The more inner shells, the greater the shielding effect and the less attractive force experienced on the outer shell electron. Shielding reduces the net attractive force.

Question 12

Definition of ionic bonding:

Answer 12

Ionic bonding is the strong electrostatic attraction between the positive and negative ions.

Question 13

Definition of covalent bonding:

Answer 13

A covalent bond is the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Question 14

Definition of a molecule:

Answer 14

A molecule is two or more atoms held together by covalent bonds.

Question 15

Definition of a lone pair:

Answer 15

A lone pair is an outer shell pair of electrons not involved in the chemical bonding.

Question 16

What is a dative (or coordinate) bond?

Answer 16

A covalent bond in which the shared pair of electrons has been donated by one of the bonding atoms only.