wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

Radioactivity

Total questions: 20

Worksheet time: 20mins

Name
Class
Date
1.

Radioactive sources are used in hospitals for both diagnosis and treatment of medical conditions, exposure of patients to ionising radiation will...(complete the sentence)

a)

decrease the probability of causing mutation of DNA in cells

b)

always cause burns

c)

never cause mutation of DNA in cells

d)

increase the probability of causing mutation of DNA in cells

2.

An electron has a charge of −1.6 × 10−19 C.

An alpha (α) particle is a helium nucleus.

A beta particle is a fast moving electron. The charge carried by an alpha particle is...

a)

−1.6 × 10−19 C

b)

+1.6 × 10−19 C

c)

−3.2 × 10−19 C

d)

+3.2 × 10−19 C

3.

Which of these is correct for half-life?

a)

It is half the time for all the atoms to decay

b)

It is the time it takes for an atom to half decay

c)

It is the time it takes for half an atom to decay

d)

It is the time it takes for half the atoms to decay

4.

Following the radioactive decay of a nucleus, the nucleus might undergo some rearrangement, losing energy as

a)

gamma radiation

b)

a proton

c)

a neutron

d)

an X-ray

5.

Iodine-123 is used as a radioactive tracer to diagnose thyroid problems. This tracer must have a half-life of

a)

a few days

b)

a few hours

c)

less than a secon

d)

several weeks

6.

Thorium and radium emit alpha radiation when they decay. Alpha radiation (complete the sentence)

a)

can penetrate a few mm of aluminium

b)

is highly ionising

c)

is a type of electromagnetic radiation

d)

has a negative charge

7.

If food has been deliberately exposed to gamma radiation, the gamma radiation is used to

a)

produce cancer cells in the food

b)

kill cancer in the food

c)

kill microbes in the food

d)

make the food radioactive

8.

Radioactive decay is sometimes described as being spontaneous. In this context spontaneous means

a)

nothing can influence the decay

b)

the decay is random

c)

the decay can be predicted

d)

the decay is exponential

9.

The ionising properties of radiations determine their penetrating power. Which of the following statements is correct?

a)

α-particles are not very ionising so they are stopped by thin paper.

b)

α-particles are very ionising so can only travel a few centimetres in air

c)

γ-radiation is very penetrating because it is very ionising

d)

γ-radiation is not very penetrating because it is very ionising

10.

A radioactive source is placed a few cm away from a detector. There is no change in the count rate when a thin aluminium foil is placed between the source and the detector, but the count rate is reduced to the background rate when a 0.5 cm aluminium plate is introduced. These observations show that the source must be emitting

a)

alpha and beta radiation.

b)

beta and gamma radiation.

c)

beta radiation only.

d)

gamma radiation only.

11.

In a famous thought experiment, Schrödinger imagined that a cat is locked in a box, along with a radioactive atom that is connected to a tube containing a deadly poison. If the atom decays, it causes the tube to smash and the cat to die. The random nature of radioactive decay means that the radioactive atom will

a)

decay after one half-life.

b)

probably decay after one half-life.0

c)

have a fixed probability of decaying in a given time interval.

d)

have a number of possible decay paths.

12.

In an experiment to measure the activity of a radioactive source the measured activity should always be corrected by

a)

adding the background count.

b)

adding the background count rate.

c)

subtracting the background count.

d)

subtracting the background count rate.

13.

The table below gives the range and number of ion pairs per centimetre produced by β particles, compared to α particles of the same energy.

Select the row from the table which shows the correct comparison.

a)

A

b)

B

c)

C

d)

D

14.

Select the row of the table that describes the relative ionisation and relative penetration of nuclear radiations.

a)

A

b)

B

c)

C

d)

D

15.

Radioactive decay is said to be a spontaneous process.

This means that

a)

we cannot know when a nucleus will decay

b)

we cannot know which nucleus will decay next

c)

we cannot know how many nuclei will decay

d)

we cannot influence when a nucleus will decay

16.

Which of these particles has the largest charge?

a)

alpha particle

b)

beta particle

c)

neutron

d)

proton

17.

Which of these particles has the largest mass?

a)

alpha particle

b)

beta particle

c)

neutron

d)

proton

18.

When a nucleus emits a beta particle

a)

the nucleon number decreases by 1

b)

the nucleon number increases by 1

c)

the proton number decreases by 1

d)

the proton number increases by 1

19.

What is the half-life of Phosphorous 32 as shown in the graph?

a)

14 days

b)

90 cpm

c)

8 days

d)

28 days

20.

Protactinium has a half-life of 70 s. A sample of protactinium is prepared and monitored over a period of time. Which of the following statements is correct?

a)

The activity of the protactinium will be zero after 140 s.

b)

The activity of the protactinium will be 25% of its initial value after 140 s.

c)

The activity of the protactinium will be 12.5% of its initial value after 280 s.

d)

The activity of the protactinium will never become zero.