Readioactivity

Question 1

Alpha radiation

Answer 1

Stoped by paper

Has the greatest ionising power

Question 2

Beta radiation

Answer 2

Went through paper

It has less ionising power than alpha but more than gamma

Question 3

Gamma radiation

Answer 3

Which is even more penetrating that beta radiation

Least ionising power

Question 4

Alpha radiation charge

Answer 4

Positive

Question 5

Radioactive substance

Answer 5

Contains an unstable nuclei that becomes stable by emitting radiation

Question 6

Ernest Rutherford discovered:

Answer 6

Most alpha particles went straight through
No. Of alpha particles which deflected decreased as the angle of deflection increased
About 1 in every 10000 alpha particles were deflected by more than 90°
Where most of the mass of the atom was located

Question 7

Plum pudding model and nuclear model in terms of the Rutherford experiment

Answer 7

The plum pudding model could not explain why some alpha particles scattered through large angles. The nuclear model of the atom was able to correctly explain this as there was a small positively charged nucleus in the centre where most of the atoms mass was located. (High density)

Question 8

Atomic number

Answer 8

Number of protons

Question 9

Mass number

Answer 9

Protons and neutrons

Question 10

Isotopes

Answer 10

Are atoms of the same element with different numbers of neutrons.

Question 11

Alpha emission

Answer 11

Alpha particle is made up of 2 protons and 2 neutrons.
Relative mass is 4 and its relative charge is +2
Represented by the symbol 4/2

Atomic number goes down by 2
And the mass number goes down by 4

Question 12

example of alpha emission:Thorium isotope decaying Th 228/90

Answer 12

Ra 224/88

Question 13

Beta emission

Answer 13

It has a negative charge 
Relative mass of a beta particle is 0 
And the relative charge is -1
Represented as 0/-1
Atomic number of nucleus goes up by 1
And the mass number is unchanged because neutron changes into proton

Question 14

Example of beta emission: potassium isotope 40/19K

Answer 14

Turns into 40/20Ca a calcium Isotope

Question 15

Half life of a radioactive substance

Answer 15

Is the average time it takes for the number of nuclei of the isotope in a sample to halve