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 1st shell hold?

Answer 3

2

Question 4

How many electrons can the 2nd shell hold?

Answer 4

8

Question 5

How many electrons can the 3rd shell hold?

Answer 5

18

Question 6

How many electrons can the 4th shell hold?

Answer 6

32

Question 7

What is an orbital?

Answer 7

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

Question 8

How many electrons can an orbital hold?

Answer 8

2

Question 9

What are the 4 types of orbitals?

Answer 9

s orbital, p orbital, d orbital, f orbital

Question 10

What is the shape of an s-orbital?

Answer 10

Spherical

Question 11

What is the shape of a p-orbital?

Answer 11

Dumb-bell shape

Question 12

How many orbitals are found in an s subshell?

Answer 12

1

Question 13

How many electrons can be held in an s subshell?

Answer 13

2

Question 14

How many orbitals does a p subshell have?

Answer 14

3

Question 15

How many electrons can be held in a p subshell?

Answer 15

6

Question 16

How many orbitals are present in a d subshell?

Answer 16

5

Question 17

How many electrons can be held in a d subshell?

Answer 17

10

Question 18

How many orbitals are found in an f subshell?

Answer 18

7

Question 19

How many electrons can fill an f subshell?

Answer 19

14

Question 20

When using ‘electrons in box’ representation, what shape is used to represent the electrons?

Answer 20

Arrows. The first two electrons pair up in the 1s orbital, the next two pair up in the 2s orbital, and the last three singly occupy the three 2p orbitals with the same spin.

Question 21

What letter is used to represent the shell number?

Answer 21

n

Question 22

From which shell onwards is the s orbital present?

Answer 22

n = 1

Question 23

From which shell onwards is the p orbital present?

Answer 23

n = 2

Question 24

From which shell onwards is the d orbital present?

Answer 24

n = 3

Question 25

From which shell onwards is the f orbital present?

Answer 25

n = 4

Question 26

What are the rules by which electrons are arranged in a shell?

Answer 26

1. Electrons are added one at a time. 2. Lowest available energy level is filled first. 3. Each energy level must be filled before the next one can fill. 4. Each orbital is filled singly before pairing. 5. 4s is filled before 3d.

Question 27

Why does the 4s orbital fill before the 3d orbital?

Answer 27

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

Question 28

What is the electron configuration of krypton?

Answer 28

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

Question 29

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

Answer 29

Electrons in the highest energy levels