EL 3 & 4

Question 1

What are shells made up of?

Answer 1

• Sub-shells
• Orbitals

Question 2

Which shells have greater energy levels?

Answer 2

Shells further from the nucleus

Question 3

How many electrons can orbitals hold?

Answer 3

2

Question 4

What are the 4 types of sub-shells in order?

Answer 4

S p d f

Question 5

How many orbitals does each sub shell have?

Answer 5

S - 1
P - 3
D - 5
F - 7

Question 6

What are the maximum number of electrons in each sub-shell?

Answer 6

S - 2
P - 6
D - 10
F - 14

Question 7

What sub-shells are in the first shell?

Answer 7

1s

Question 8

What sub-shells are in the second shell?

Answer 8

2s 2p

Question 9

What sub-shells are in the third shell?

Answer 9

3s 3p 3d

Question 10

What sub-shells are in the fourth shell?

Answer 10

4s 4p 4d 4f

Question 11

What are orbitals?

Answer 11

A region of space which has a 95% chance of holding 2 electrons

Question 12

What happens in orbitals?

Answer 12

Spin pairing - electrons in orbitals spin in opposite directions

Question 13

What are the 2 main shapes of orbitals?

Answer 13

S orbital
P orbital

Question 14

How do electrons fill orbitals?

Answer 14

Singly before they start pairing up

Question 15

How is the periodic table organised?

Answer 15

By increasing atomic number

Question 16

How do you write the electronic configuration of Ca (Z20)?

Answer 16

1s2 2s2 2p6 3s2 3p6 4S2

Question 17

How do you work out the configuration of an ion up to Ca?

Answer 17

• Write down electronic structure
• Add or remove electrons to or from the highest-energy occupied shell

Question 18

How do you work out the configuration of an ion in d-block?

Answer 18

Fill the 4s sub-shell before the 3d sub-shell

Question 19

Why does melting/boiling point increase across period 1 to period 3?

Answer 19

• giant metallic bonding is strong
• Each group contributes more electrons to the sea of delocalised electrons

Question 20

Why does melting/boiling point decrease across period 5 to period 8?

Answer 20

• simple molecular bonding (molecules are held together by weak intermolecular bonds)

Question 21

Why does reactivity increase down a group?

Answer 21

• Number of shells increases
• Shielding increases
• Atomic radius increases
• First ionisation energy decreases

Question 22

What is first ionisation energy?

Answer 22

The amount of energy required to remove the outer electron

Question 23

What is periodicity?

Answer 23

Trends : a regular variation in properties of element with atomic number and position in the periodic table