2.2.1: Electron structure

Question 1

What does the principal quantum number indicate?

Answer 1

The shell occupied by the electrons

Question 2

What is a shell?

Answer 2

A group of orbitals with the same principal quantum number

Question 3

How many electrons can the 3rd shell hold?

Answer 3

18

Question 4

How many electrons can the 4th shell hold?

Answer 4

32

Question 5

What is an orbital?

Answer 5

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

Question 6

How many electrons can an orbital hold?

Answer 6

2

Question 7

What are the 4 types of orbitals

Answer 7

● s orbital
● p orbital
● d orbital
● f orbital

Question 8

`What is the shape of a s-orbital?

Answer 8

Spherical

Question 9

What is the shape of a p-orbital?

Answer 9

dumbbell shape

Question 10

How many orbitals are found in a S subshell?

Answer 10

1

Question 11

How many electrons can be held in a S subshell?

Answer 11

2

Question 12

How many orbitals does P subshell have?

Answer 12

3

Question 13

How many electrons can be held in a P subshell?

Answer 13

6

Question 14

How many orbitals are present in a D subshell?

Answer 14

5

Question 15

How many electrons can be held in a d-sub shell?

Answer 15

10

Question 16

How many orbitals are found in a F subshell?

Answer 16

7

Question 17

How many electrons can fill F subshell?

Answer 17

14

Question 18

From which shell onwards is S orbital present?

Answer 18

n=1

Question 19

From which shell onwards is P orbital present?

Answer 19

n=2

Question 20

From which shell onwards is D orbital present?

Answer 20

n=3

Question 21

From which shell onwards is F orbital present?

Answer 21

n=4

Question 22

What are the rules by which electrons are arranged in a shell? (5 marks)

Answer 22

● Electrons are added one at a time
● Lowest available energy level is filled first
● Each energy level must be filled before the next one can fill
● Each orbital is filled singly before pairing
● 4s is filled before 3d

Question 23

Why does 4s orbital fill before 3d orbital?

Answer 23

4s orbital has a lower energy than 3d before it is filled

Question 24

What is the electron configuration of krypton?

Answer 24

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

Question 25

Which electrons are lost when an atom becomes a positive ion?

Answer 25

Electrons in the highest energy levels