P2.5 Radioactive Substances Flashcards Preview

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Flashcards in P2.5 Radioactive Substances Deck (23)
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1
Q

Is the effect of beta/gamma the same inside the body as out?

A

Yes

2
Q

Effects of beta/gamma inside and outside the body

A

Dangerous, reaches cells throughout the body

3
Q

Effect of alpha outside the body

A
  • Some danger
  • Can be absorbed by skin
  • Can damage skin cells
4
Q

Effect of alpha inside the body

A

Very dangerous, affects surrounding tissue

5
Q

4 sources of background radiation

A

Cosmic rays
Food/Drink
Air travel
Medical (X-Rays)

6
Q

Define ‘half-life’

A

Time taken for the number of nuclei of the isotope in a sample to halve

7
Q

Give 3 uses of radiation

A

ANY FROM

Sterilising medical instruments, smoke detectors, killing cancer cells, chemical tracers

8
Q

Why are medical/chemical tracers safe to use?

A

Not poisonous

Short half-life, decays before damage

9
Q

What type of radiation is used for medical tracers? Why?

A

Gamma and beta; alpha can’t pass through skin

10
Q

The patient drinks water containing a tiny amount of the radioactive substance. True or False?

A

True

11
Q

A detector graph goes up then slants back down. What does this tell you?

A

Radioactive substance has gone in and out of the healthy kidney

12
Q

What would happen to a radioactive substance put through a blocked kidney?

A

It would go in but wouldn’t come back out

13
Q

What would the detector graph show for a blocked kidney?

A
The graph would go up and not come back down
|      \_\_\_\_\_\_\_\_\_\_\_\_
|    /
|  /
|/\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
14
Q

3 ways to limit exposure to radiation

A

Step AWAY from the source (long handles)
Limit TIME with ‘at risk’ (of radiation) areas
Thick concrete BARRIERS/thick lead plates (shield)

15
Q

What did Rutherford and Marsden find out about the nucleus?

A
  • Positive, it repels alpha

- Much smaller than an atom; because most alpha not deflected

16
Q

What charge does gamma have?

A

No charge, it’s an EM wave

17
Q

If you have a magnetic field and aim a beam of light through it, what would the results look like? Explain the result of beta. (Separating radiation)

A
  • Gamma would go straight through
  • Alpha would deflect at a small angle
  • Beta would deflect in the opposite direction at a larger angle BECAUSE IT’S OPPOSITELY CHARGED AND LIGHTER
18
Q

How does uranium dating work?

A

Radioactive uranium in igneous rocks has a very long half life. Each U atom days into an atom of Pb.

19
Q

How does carbon dating work?

A

Living wood contains a tiny proportion of radioactive carbon with a long half life. The amount of C in a dead tree decreases.

20
Q

What is a radioactive substance?

A

A substance that gives off radiation from the nuclei of its atoms all the time

21
Q

In every half life, what decreases by half?

A

The number of atoms of a radioactive isotope and the activity

22
Q

What is the activity of a radioactive source?

A

The number of nuclei that decay per second

23
Q

“Radioactive decay is a random process.” Yes or No? If not, why?

A

Yes, it’s random