Electrons and bonding

Question 1

What is the number of electrons which fill the first four shells

Answer 1

2, 8, 18, 32

Question 2

What are shells?

Answer 2

They are regarded as energy levels, the energy increases as the shell number increases

Question 3

What are orbitals

Answer 3

A region around the nucleus which can hold up to 2 electrons with opposite spins

Question 4

What are the different types of sub shells

Answer 4

S, P, D and F

Question 5

S sub shell

Answer 5

The electron cloud is in the shape of a sphere. Each S subshell has 2 electrons (one orbital) in it.

Question 6

P sub shell

Answer 6

The electron cloud is in the shape of a dumb-bell. Contains 6 electrons (3 orbitals) and is present from the second shell upwards.

Question 7

D sub shells

Answer 7

Is from the third shell upwards and has 10 electrons (5 orbitals).

Question 8

Sub shells

Answer 8

Within a shell orbitals of the same type are grouped together as sub shells.

Question 9

Filling up orbitals

Answer 9

The sub shells are filled up in order of increasing energy. However 4s gets filled up before 3d. When filling up sub shells with several orbitals, fill each orbital singly before pairing the up with electrons.

Question 10

How are orbitals displayed

Answer 10

An example would be 4s^2. The number represents the shell and the letter the sub shell. The last number represents the orbital. They are also shown as arrows, one pointing up and the other pointing down.