[Part 2]- P7-Atomic structure ☣️⚛️

Question 1

What is radioactive decay?

Hint: isotopes decay into…

Answer 1

• Radioactive decay, is when unstable isotopes decay into elements and give out radiation as they try to become more stable.
• They then try to balance the number of protons and neutrons, in their nucleus.

Question 2

How is alpha radiation used in smoke detectors?

Hint: ionises, smoke in air—>current stops, alarm sounds

Answer 2

• It ionises air particles, causing a current to flow.
• If there’s smoke in the air, it then binds to the ions- which means the current stops, and the alarm sounds.

Question 3

What does a Geiger counter do?

Hint: particle of _________ enters the tube.

Answer 3

A geiger counter detects radioactivity, and clicks each time a particle of radiation enters the tube.

Question 4

What is background radiation?

Answer 4

• background radiation, is radiation that exists around us all the time

Question 5

Name five places where background radiation can come from [5]

Hint: cosmic

Answer 5

• radon gas from the ground
• food and drinks
• buildings and the ground
• artificial sources
• cosmic rays

Question 6

Can you name some artificial sources of radiation?

Answer 6

• nuclear power and weapon testing
• medical reasons (e.g- chemotherapy)

Question 7

What is Bequerls, Bq ?

Answer 7

• Bequerels is the count rate of radioactivity

Question 8

What is ionisation?

Answer 8

• Ionisation causes atoms to gain or lose electrons, which forms ions.

Question 9

What is irradiation?

Answer 9

Irradiation is exposure to (nuclear) radiation

Question 10

What is contamination?

Answer 10

• Contamination is when radioactive particles, get into objects.
• [contamination is the unwanted presence of materials, that contain radioactive atoms on other materials]

Question 11

What is the difference between irradiation and contamination?

Answer 11

Irradiation is exposure to radiation ; Contamination is when radioactive particles, get into objects.

Question 12

What ionising power does alpha, beta and gamma radiation?

Hint: most

Answer 12

Alpha=most ionising power

Beta= lower ionising power

Gamma= lowest ionising power

Question 13

What is the penetrating power of alpha, beta and gamma radiation?

Hint: lowest, …, …

Answer 13

Alpha= lowest penetrating power (because it ionises the air)

Beta= lower penetrating power

Gamma= highest penetrating power [and is the most penetrating]

Question 14

What is the range in air of alpha, beta and gamma radiation?

Answer 14

Alpha= a few cm in the air

Beta= several metres in the air

Gamma= long distances through the air

Question 15

What can be used to stop: alpha, beta and gamma radiation?

Answer 15

Alpha= stopped by paper and skin

Beta= stopped by thin, aluminium foil

Gamma= lead and thick concrete

Question 16

What are ways to reduce the risk of irradiation?

Hint: remote control, keep sources, stand

Answer 16

• keep radioactive sources in lead- lined boxes
• stand behind barriers when using radioactive sources
• in industries, the radioactive source may be in a different room and remote controlled.

Question 17

What are ways to reduce the risk of contamination?

Hint: protective

Answer 17

• use gloves or tongs when handling radioactive sources
• in industrial purposes, wear protective suits to stop breathing in particles.

Question 18

Why are beta and gamma the most dangerous sources of radiation, outside of the body? (Compared to alpha radiation)

Answer 18

• beta and gamma can penetrate through the body, and get to delicate organs
• However, alpha radiation is less dangerous as it can’t penetrate the skin + is easily blocked by a small air gap

Question 19

Inside of our bodies, which source of radiation is the most dangerous and why?

Hint: localised area

Answer 19

• Inside of our body, alpha sources are the most dangerous because they do damage in a localised area.
• This is why contamination, compared to irradiation is a major concern when handling alpha sources.

Question 20

Inside of our bodies, which is the lower danger of radiation? Why

Hint: radiation is absorbed over a wider area

Answer 20

• Inside of our bodies, beta sources are the less dangerous because radiation is absorbed over a wider area. Meaning some passes out of the body

Question 21

Which type of radiation, is the least dangerous, inside of our body?

Hint: think about ionising power

Answer 21

• But overall, gamma sources are the least dangerous inside of our body.
• This is because they pass straight out, due to having the lowest ionising power.

Question 22

Why is peer reviewing important?

Hint: published + shared

Answer 22

• Peer reviewing is important, because scientists findings’ can be published and shared, so their findings can be checked by other scientists.