5.1 Electron configurations and bonding

Question 1

How many electrons are there in each shell?

Answer 1

1 = 2
2 = 8
3 = 18
4 = 32

Question 2

What is an atomic orbital?

Answer 2

A region of an atom around the nucleus that can hold up to 2 electrons, with opposite spins.
Has a high probability of finding an electron

Question 3

How many electrons can each orbital hold?

Answer 3

2

Question 4

What are the 4 types of sub-level?

Answer 4

s
p
d
f

Question 5

How many orbitals in an s sub-level?

Answer 5

1

Question 6

How many orbitals in a p sub-level?

Answer 6

3

Question 7

How many orbitals in a d sub-level?

Answer 7

5

Question 8

How many orbitals in an f sub-level?

Answer 8

7

Question 9

Max number of electrons in an s sub-level

Answer 9

2

Question 10

Max number of electrons in a p sub-level

Answer 10

6

Question 11

Max number of electrons in a d sub-level

Answer 11

10

Question 12

Max number of electrons in an f sub-level

Answer 12

14

Question 13

What is the shape of an s orbital?

Answer 13

Circle

Question 14

What is the shape of the p orbitals?

Answer 14

3 infinity symbols overlapping
one horizontal, one vertical and one diagonal

Question 15

The radius of the S orbital increases…

Answer 15

As the shell number increases and it gets further away from the nucleus

Question 16

What is different about 4s and 3d?

Answer 16

4s is at a lower energy level than 3d so is filled first
This is the same for all s and ds beyond 3

Question 17

Why must the electrons spin in opposite directions?

Answer 17

To counteract the repulsion between the two negative charges of the electrons

Question 18

How do electrons fill up orbitals?

Answer 18

One electrons occupies each orbital before pairing starts as pairing requires more energy to occur

Question 19

How would you write the electron configuration of nitrogen?

Answer 19

N: 1s^2 2s^2 2p^3

Question 20

What does the little number above the sub-level letter mean?

Answer 20

The number of electrons in that sub-level

Question 21

What does the coefficient of the sub-level name mean when writing electron configurations?

Answer 21

The shell number/ energy level

Question 22

What is the Aufbau Principle?

Answer 22

states that electrons must occupy the lowest energy level first

Question 23

What is Pauli’s Extension Prinicple?

Answer 23

only 2 electrons in the same orbital and they must have opposite spins

Question 24

What is Hund’s rule of maximum multiplicity?

Answer 24

electrons prefer to occupy orbitals on their own and only pair up when no empty orbitals of the same energy level are available

Question 25

Exceptions: electron structure of Chromium

Answer 25

1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^5

Question 26

Exceptions: electron structure of Copper

Answer 26

1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^10

Question 27

Sub-shell order of filling:

Answer 27

1s - 2s - 2p - 3s - 3p - 4s - 3d - 4p - 5s...

Question 28

Shorthand versions of electron configurations:

Answer 28

Use the previous noble gas in [] then the rest of the electron shells

Question 29

How do you work out the electron configurations of ions?

Answer 29

Remove/add electrons to next available energy level 4s fills and empties before 3d