P4.3 Radioactive Emissions

Question 1

What is radioactive decay?

Answer 1

Radioactive decay is the process by which unstable atomic nuclei emit radiation to become more stable. This radiation can take the form of high-energy particles (alpha, beta, neutrons) or electromagnetic waves (gamma rays)

Question 2

Is Radioactive decay random?

Answer 2

Yes, we cannot predict when it will happen

Question 3

What is half life?

Answer 3

Half life is the average time taken for half the amount of the unstable nuclei in a sample to decay

Question 4

What happens after a nucleus decays?

Answer 4

It could become stable

Question 5

How is radioactivity of a source measured?

Answer 5

Geiger Muller tube

Question 6

What do unstable nucleus emit?

Answer 6

Radiation

Question 7

What does a nucleus become stable mean?

Answer 7

Nucleus emits radiation to become more stable

Question 8

What does radioactive mean?

Answer 8

radioactive refers to materials containing unstable atomic nuclei.

Question 9

What does an alpha particle contain?

Answer 9

2 protons
2 neutrons
Same as Helium

Question 10

Does an alpha particle contain electrons?

Answer 10

No

Question 11

How good at penetrating is an alpha particle?

Answer 11

Low

Question 12

How ionising is an alpha particle?

Answer 12

Very

Question 13

What does an alpha particle do to an electron

Answer 13

Knocks it out its shell

Question 14

What particle is a beta particle the same as?

Answer 14

Electron

Question 15

What happens when one of the neutrons decay?

Answer 15

Decays into a proton and electron

Question 16

What happens to the proton and electron which have been formed by the neutron in beta decay?

Answer 16

Proton stays in nucleus
Electron is emitted out at high speeds

Question 17

How ionising and penetrating is beta radiation?

Answer 17

Moderately ionising and penetrating

Question 18

What is gamma radiation?

Answer 18

Waves of electromagnetic radiation

Question 19

When is gamma radiation normally emitted?

Answer 19

After, beta and alpha

Question 20

True or False:
Gamma Rays have no charge or mass

Answer 20

True

Question 21

How ionising and penetrating are gamma rays?

Answer 21

Ionising - weak
Penetrating - strong

Question 22

What is neutron emission?

Answer 22

Neutrons being emitted because there are too many, so neutrons are thrown out by nucleus to increase stability

Question 23

What is ionising radiation?

Answer 23

Removing electrons to form positively charged ions

Question 24

In nuclear decay does the equation need to be balanced?

Answer 24

Yes

Question 25

How do you know if its a Beta, Alpha or neutron equation?

Answer 25

n = neutron 2 elements = alpha e = beta

Question 26

What does contamination mean?

Answer 26

Radioactive material inside body or on skin, cant be removed

Question 27

What does irradiation?

Answer 27

Radioactive material outside the body but can travel inside

Question 28

What is the energy of a photon proportional to?

Answer 28

Frequency

Question 29

Explain what happens when atoms absorb electromagnetic radiation?

Answer 29

Photons excite electron to higher energy level. When the electron moves from lower to higher energy level its called excited

Question 30

Can it be any amount of energy to excite the electron?

Answer 30

No, the photon has to have the exact amount of energy

Question 31

What photons have enough energy to completely remove an electron?

Answer 31

Photons of Ultra-Violet, Xray and Gamma rays.