Atomic Structure

Question 1

What is the plum pudding model?

Answer 1

A model of the atom where the atom consisted of positively charged sphere with a lot of negative electrons stuck in it.
Proposed by J.J Thomson

Question 2

What is the nuclear model?

Answer 2

Current model of positively charged nucleus of protons and neutrons, orbited by negatively charged electrons.
Proposed by Ernest Rutherford

Question 3

What is alpha (α) radiation?

Answer 3

2 neutrons and 2 protons
Same as Helium nucleus.
Atomic No = -2
Mass No = -4

Question 4

What is the electric charge of alpha radiation?

Answer 4

+2

Question 5

What is the relative atomic mass of alpha radiation?

Answer 5

4

Question 6

How penetrating is alpha radiation?

Answer 6

Stopped by paper or a few centimetres of air

Question 7

How ionising is alpha radiation?

Answer 7

Strongly ionising

Question 8

What is effect of magnetic field of alpha particle?

Answer 8

Strongly deflected

Question 9

What is beta (β) radiation?

Answer 9

High energy electron
A neutron changes to a proton
Atomic No. = +1
Mass No. = +0

Question 10

What is the electric charge of beta radiation?

Answer 10

-1

Question 11

What is the relative atomic mass of beta radiation?

Answer 11

1/1860

Question 12

How penetrating is beta radiation?

Answer 12

Stopped by a few millimetres of aluminium

Question 13

How ionising is is beta radiation?

Answer 13

Weakly ionising

Question 14

What is the effect of the magnetic field of beta radiation?

Answer 14

Strongly deflected

Question 15

What is Gamma (y) radiation?

Answer 15

High energy electromagnetic radiation
Atomic No = +0
Mass No = +0

Question 16

What is the electric charge of gamma radiation?

Answer 16

0

Question 17

What is the relative atomic mass of gamma radiation?

Answer 17

0

Question 18

What is the penetrating power of gamma radiation?

Answer 18

Stopped by several centimetres of lead or several metres of concrete

Question 19

How ionising is gamma radiation?

Answer 19

Very weakly ionising

Question 20

What is the effect of the magnetic field of gamma radiation?

Answer 20

Not deflected

Question 21

What is radioactivity?

Answer 21

Some atomic Isotopes are unstable and emit radiation so they become more stable this process is called Radioactive Decay.

Question 22

What are the 3 types of radiation?

Answer 22

• Alphaα
• Beta β
• Gamma γ

Question 23

What is ionisation?

Answer 23

When radiation hits an atom it can cause it to lose electrons.
The positively charged atom produced is called an ion, and this process is called ionisation

Question 24

What is radioactivity measured by/with?

Answer 24

Measured in Becquerel (Bq)

Decay is measured by a Geiger-Muller tube (eg a Geiger Counter)