Subshells and energy levels

Question 1

What are shells made of?

Answer 1

Shells (principle quantum shells) are made of sub shells and they are made of orbitals

Question 2

What is the principle quantum number?

Answer 2

The number of shells

Question 3

What does a higher shell number mean?

Answer 3

The higher the energy of electrons in each shell

Question 4

What are the labels of sub shells and their energy levels?

Answer 4

s,p,d and f and they increase s<p<d<f

Question 5

What is shell 1?

Answer 5

It is only one sub shell, which is an s sub shell, so it is labelled the 1s sub shell

Question 6

What is shell 2?

Answer 6

It contains 1 s subshell and 1 p subshell, labelled the 2s subshell and the 2p subshell

Question 7

What is shell 3?

Answer 7

Contains 1 s subshell, 1 p subshell and 1 d subshell, labelled the 3s subshell, 3p subshell and 3d subshell

Question 8

What are s subshells

Answer 8

They are made of 1 orbital and can hold a maximum of 2 electrons

Question 9

What is the p subshell?

Answer 9

It is made up of 3 orbitals and can hold a maximum of 6 electrons

Question 10

What is the d subshell?

Answer 10

It is made up of 5 orbitals and can hold a maximum of 10 electrons

Question 11

Why are orbitals degenerate?

Answer 11

In any subshell, all orbitals have the same energy level

Question 12

What are orbitals?

Answer 12

Regions which can hold up to a pair of electrons with opposite spins

Question 13

How many electrons have an orbital hold?

Answer 13

A maximum of 2 each

Question 14

What are the different types of orbital?

Answer 14

s, p, d and f

Question 15

What is the shape of an s orbital?

Answer 15

Spherical ( O )

Question 16

What is the shape of a p orbital?

Answer 16

Dumbbell ( OO )

Question 17

What is the maximum number of electrons in the first shell?

Answer 17

2

Question 18

What is the maximum number of shells in the second shell?

Answer 18

8

Question 19

What is the maximum number of shells in the third shell?

Answer 19

18

Question 20

How are electrons represented when drawn?

Answer 20

As arrows and if there are 2, one arrow is up and one is down

Question 21

What is Hund’s rule?

Answer 21

When filling a subshell, a single electron must be present in every orbital before a second one is added

Question 22

How is the 4s subshell filled?

Answer 22

It is filled first when drawing a diagram but when it is written out, all the ‘3’ subshells are kept together

Question 23

What is the electron configuration of copper?

Answer 23

1s2 2s2 2p6 3s2 3p6 3d10 4s1

Question 24

What is the electronic configuration of chromium?

Answer 24

1s2 2s2 2p6 3s2 3p6 3d5 4s1

Question 25

How can electron configurations be shortened?

Answer 25

By using the symbol of the noble gas from the previous period and additional configuration, e.g, Zn = [Ar] 3d10 4s2

Question 26

What is the s block of elements?

Answer 26

Group 1 & 2 and helium

Question 27

What is the p block of elements?

Answer 27

Groups 3 (excluding transition metals) to 8 (excluding helium)

Question 28

What is the d block of elements?

Answer 28

The transition metals

Question 29

What is the f block of elements?

Answer 29

The lanthanides and actinides

Question 30

Why are elements sorted into blocks?

Answer 30

It is based of which subshell their outmost electron is in

Question 31

Why is there a decrease in first ionisation energy from group 2 to group 3?

Answer 31

Because less energy is required to remove electrons from the p subshell as it is a higher energy subshell so it is easier to remove the outer electron so first ionisation energy is lower

Question 32

Why is there a decrease in first ionisation energy from group 5 to 6?

Answer 32

Because in group 6, there is a pair of electrons in the first orbital so they repel eachother. This means less energy is required to remove electrons from paired subshells due to repulsion so less energy is required to remove the outer electron, the first ionisation energy is lower