Atomic physics

Question 1

Number of protons and neutrons

Answer 1

Same number

Question 2

What is a isotope

Answer 2

Atoms of the same element with the same number of protons and electrons, but different number of neutrons

Question 3

Describe the random nature of radioactive emission

Answer 3

There is a probability that a specific isotope will emit an alpha, beta, gamma particle

Question 4

The nature of Alpha particles

Answer 4

• Has a positive charge
• Identicle with helium nuclei
• Two protons and neutrons

Question 5

The nature of Beta particles

Answer 5

• Has a negative charge
• Has no mass
• High speed electrons

Question 6

The nature of Gamma rays

Answer 6

• No mass and charge
• Electromagnetic waves
• High frequency and high energy

Question 7

Ionising effect of Alpha particle

Answer 7

• Highly ionising due to large mass and charge
• Removes electrons from objects it encounters

Question 8

Ionising effect of Beta particle

Answer 8

• Does not always displace electrons when colliding with a atom because no mass
• Mildly ionising

Question 9

Ionising effect of Gamma rays

Answer 9

• Because they have no mass and charge, they weakly ionise

Question 10

Penetrating abilities of Alpha particles

Answer 10

• Least penetrating
• Only travel through air about 5 cm
• Stopped by materials like thin paper or skin
• Large mass, so less penetration

Question 11

Penetrating abilities of Beta particles

Answer 11

• Can travel through skin
• Stopped by few milimeters of aluminium
• Small in size, so greater penetration

Question 12

Penetrating abilities of Gamma rays

Answer 12

• Most penetrating
• Bc No mass and charge
• Can only be stopped by thick lead or concrete

Question 13

Deflection of Alpha particles in electric field

Answer 13

• They are repelled by the positive plate and attracted by the negative or neutral plate
• Deflected by a small amount because of large mass compared to charge (newtons second law f = ma)

Question 14

Deflection of Beta particles in electric field

Answer 14

• Attracted to the positive plate
• Deflected by a large amount because very small mass compared to charge

Question 15

Deflection of Gamma rays in electric field

Answer 15

• Their path is not altered due to no charge by the presence of electric field
• Moves straight through

Question 16

Deflection in Magnetic field

Answer 16

Can be found through the left hand rule

Question 17

Use of Alpha particles

Answer 17

Smoke detector- Alpha particles collide with smoke which breaks the flow of charge which cause the alarm

Question 18

Use of Beta particle

Answer 18

Test and control thickness of materials - Sends feedback if too thick or thin