Radiation

Question 1

What is an isotope

Answer 1

Same number of protons different number of neutrons

Question 2

How can an electron change orbit

Answer 2

They absorb energy (radiation)

Question 3

What is ionisation

Answer 3

When an electron gains too much radiation it can escape from the atom completely

Question 4

What are the dangers of ionising radiation

Answer 4

-causes cells to mutate=cancer

Question 5

What is alpha radiation

Answer 5

When an alpha particle is emitted from the nucleus so the atom becomes a different element

Question 6

What is positron decay

Answer 6

During positron decay a proton turns into a neutron and a positron is emitted from nucleus and an atom becomes a different element.

Question 7

Features of positron decay

Answer 7

-+1 charge
-positron annihilates immediately
-positron is a type of antimatter

Question 8

Positron decay equation:

Answer 8

23 23 0
Mg ————> Na + e
12 11 1

Question 9

Features of alpha radiation

Answer 9

-stopped by paper
-2+ charge
-strongly ionising
-range of a few cm in the air
-dangerous inside

Question 10

What is beta minus

Answer 10

When a beta particle is emitted from the nucleus the atom becomes a different element

Question 11

Features of beta minus radiation

Answer 11

-stopped by thin aluminium
-1- charge
-weakly ionising
-range of a few m in air

Question 12

Beta minus equation

Answer 12

14. 14. 0
        C———>. N + e
15. 7. 1

Question 13

Give an approximation for the radius of an atom

Answer 13

1x10^-10 metres

Question 14

What are the three subatomic constituents of an atom?

Answer 14

1. Proton
2. Neutron
3. Electron

Question 15

Where is most of the mass of an atom concentrated?

Answer 15

In the nucleus

Question 16

What proportion of the total radius of an atom is the radius of the nucleus?

Answer 16

1/10,000

Question 17

Describe the arrangement of protons neutrons and electrons in an atom

Answer 17

• Protons and neutrons are found in the atoms nucleus
• Electrons are found in discrete energy levels around the nucleus

Question 18

What is charge of nucleus
Why?

Answer 18

+ charge
Nucleus has protons and neutrons neutrons have no charge protons are positive.

Question 19

Give two ways that an atoms electron arrangement can be changed.

Answer 19

1. Absorbing electromagnetic radiation
2. Emitting electromagnetic radiation

Question 20

What happens to an atoms electron arrangement when it absorbs EM radiation.

Answer 20

• Electrons move to higher energy levels
• They move away from the nucleus

Question 21

What happens to an atoms electron arrangement when it emits EM radiation

Answer 21

• Electrons move to a lower energy level
• They move towards the nucleus

Question 22

What do all forms of the same element have in common

Answer 22

The number of protons

Question 23

Atomic number

Answer 23

Number of protons in an atom

Question 24

Mass number

Answer 24

Total number of protons and neutrons

Question 25

How do atoms turn into positive ions?

Answer 25

- They lose one or more of their outer electrons

Question 26

State four types of nuclear radiation

Answer 26

1. Alpha particles 2. Beta particles 3. Gamma rays 4. Neutrons