1.3 Arrangement of electrons

Question 1

What did Bohr find in 1913

Answer 1

Atom consists of tiny positive nucleus and its orbited by negative electrons to form an atom like solar system.

Electrons orbit in shells of fixed size and the movement of electrons from one shell to the next explains how atoms absorb and emit light.

Quantum theory

Question 2

What did Schrödinger find in 1926

Answer 2

Found an equation that used the idea that electrons have some of the properties of waves as well as of particles.

This lead to Quantum mechanics which is used to predict the behaviour of sub atomic particles

Question 3

What did Chadwick discover in 1932

Answer 3

He discovered the neutron

Question 4

What did Gilbert Lewis discover in 1932

Answer 4

. The inertness of the noble gases is related to having a full outer shell of electrons

. Ions are formed by atoms losing or gaining electrons to attain full outer shells

. Atoms can bond by sharing electrons to form full outer shells

Question 5

What is the latest theory surrounding the electron

Answer 5

It’s not a solid particle, It’s a smeared out cloud. of negative charge, so you can never say exactly where an electron is at a given moment

Question 6

What is the equation for finding the number of electrons on each shell

Answer 6

2n^2 where n is the number of shells

First shell holds 2
Second shell holds 8
Third shell holds 18

Question 7

How would you draw an electron diagram for carbon

What about for sulfur

Answer 7

It has 6 electrons so there are 2 on first shell and 4 on second shell spaced out

2,4

Sulfur has 16 electrons so there are 2 on the first shell, 8 on second shell, and 6 on third

2,8

Question 8

How can you draw electron configurations for ions eg Na+

Answer 8

Na+ has 10 electrons so draw 2 on first shell and 8 on second shell

2,8