Atomic Structure Summary review

Question 1

Draw a diagram showing the structure of an atom.

Answer 1

(Answer on google classroom)

Question 2

What is an isotope?

Answer 2

A different version of an atom for an element with the same number of protons but different numbers of neutrons

Question 3

How many protons and neutrons are found in a normal carbon nucleus?

Answer 3

6 protons, 6 neutrons and 12 is the mass number

Question 4

How many protons and neutrons are found in the nucleus of a carbon-14 isotope?

Answer 4

6 protons, 8 neutrons and it’s mass number is 14

Question 5

What is ionization?

Answer 5

Radiation removing an electron from an atom or molecule, changing it

Question 6

Describe alpha radiation

Answer 6

2 protons and 2 neutrons

Question 7

Describe beta radiation

Answer 7

High speed electron

Question 8

Describe gamma radiation

Answer 8

Electromagnetic waves

Question 9

Complete the table showing the properties of the 3 types of radiation

Answer 9

Alpha. Beta. Gamma.
Mass. . 4. Very Small. None
Charge. +2. -1. None
Absorbed by Skin/paper. Aluminum. Lead

Question 10

Complete the diagram showing how alpha, beta and gamma travel through an electric field

Answer 10

(Answer on google classroom)

Question 11

Write the decay equation for Radium 226 (alpha decay)

Answer 11

226. 4. 222. Ra. ➡️ a +. Rn.
             
             88. 2. 86.

Question 12

Write the decay equation for Polonium 218 (beta decay)

Answer 12

218. 0. 218. Po. ➡️ e. . +. At
             84. -1. 85

Question 13

What is half-life?

Answer 13

The time taken for the amount of radiation from a source to decrease by half

Question 14

Sketch a graph showing a half-life of 2 days.

Answer 14

(Answer on google classroom)

Question 15

Strontium 90 has a half-life of 28 years. How long will it take to fall to less than 1% of it’s original activity?

Answer 15

0 years = 100%
28 years (1 half life) = 50%
56 years (2 half lives) = 25%
…
196 years (7 half-lives) = 0.78%

Question 16

The activity of a sample of Uranium 235 is 640 Bq. Two hours later it has fallen to 40 Bq. What is its half-life?

Answer 16

640 → 40 = 4 half lives
4 half lives in 120minutes (two hours) Half life = 30 minutes

Question 17

What is nuclear fission?

Answer 17

Splitting a nucleus releasing energy

Question 18

What is nuclear fusion?

Answer 18

Joining two nuclei together releasing energy

Question 19

What is the difference between contamination and irradiation?

Answer 19

Irradiation = Exposure to radiation from a source that is outside your body
Contamination = Exposure to radiation from a source that is inside your body

Question 20

What is background radiation?

Answer 20

Radiation that is always in the atmosphere from cosmic rays, rocks, radon gas and other sources

Question 21

Describe how radiation can be used to measure thickness

Answer 21

A radioactive source is placed on one side of the item and a detector on the other. Alpha can be used to measure paper thickness, beta can be used for metals. The thickness of the material will affect the amount of radiation detected on the other side.

Question 22

Describe how radiation can be used as a medical tracer

Answer 22

The patient eats/drinks or is injected with a radioactive source. After a few hours a camera which detects radiation is used to scan the body. Radiation will be emitted from wherever the source has travelled (eg through the digestive system)