small physics test

Question 1

types of energy transfers (4)

Answer 1

heating by radiation
mechanical/work

electrical/work
kinetic (particles)

Question 2

alpha radiation + ionising properties + penetrating powers + distance + charge

Answer 2

• (alpha particles)2 protons and 2 neutrons
• strongly ionising
• stopped by paper
• a few centimetres
• positive (attracted to negative) (2+)

Question 3

beta radiation (process) + ionising properties + penetrating powers + distance + charge

Answer 3

• high energy electrons form when a neutron splits into a proton and an electron
• moderately ionising
• stopped by aluminium
• tens of centimetres
• negative (attracted to positive) (-1)

Question 4

gamma radiation + ionising properties + penetrating powers + distance + charge

Answer 4

• electromagnetic wave
• not very ionising
• stopped by concrete and lead
• very large distances
• neutral (0)

Question 5

what happens to radiation after it travels for very large distances? (2)

Answer 5

• radiation becomes less intense as it travel further away from the radioactive material
• because the particles or rays become more spread out.

Question 6

what is half life

Answer 6

how long it takes for half the nuclei of a piece of radioactive material to decay.

Question 7

what happens to unstable nuclei

Answer 7

radioactive decay. they breakdown and change into a completely different type of atom.

Question 8

what is an isotope

Answer 8

an atom with the same number of protons to an element but a different number of neutrons

Question 9

ways of detecting radiation

and how?

Answer 9

• photographic film (gets darker when it absorbs radiation)

- Geiger-Muller tube (Each time it absorbs radiation, it transmits an electrical pulse to a counting machine.)

Question 10

natural sources of background radiation (3)

Answer 10

cosmic rays - radiation that reaches the Earth from space

rocks and soil - some rocks are radioactive and give off radioactive radon gas

living things - plants absorb radioactive materials from the soil and these pass up the food chain

Question 11

artificial sources of background radiation

Answer 11

• x rays
• nuclear weapons
• nuclear power

Question 12

alpha symbol is a nuclear equation

Answer 12

4
α

2

Question 13

beta symbol in a nuclear equation

Answer 13

0
β-

-1

Question 14

neutron symbol is a nuclear equation

Answer 14

1
n

0

Question 15

gamma symbol in nuclear equation

Answer 15

γ

Question 16

what is irradiation?

Answer 16

Exposing objects to beams of radiation

Question 17

what is contamination?

Answer 17

radioactive material is introduced into (or onto) an object.

Question 18

what are the two types of radiation?

Answer 18

electromagnet and nuclear

Question 19

where does nuclear radiation come from?

Answer 19

atomic nucleus from unstable isotopes

Question 20

why is nuclear radiation released?

Answer 20

gives atoms greater stability

Question 21

name a source of radiation

Answer 21

radon

Question 22

define unstable nuclei

Answer 22

some nuclei are unstable, to become stable they fall apart; the particles and energy that are lost are called radiation

Question 23

why is radiation dangerous?

Answer 23

radiation is ionising, it can damage DNA, causing cell mutations and therefore cancer

Question 24

define ‘ionising’

Answer 24

electrons leaving atoms

Question 25

beta + decay (positron)

Answer 25

a proton becomes a neutron and a positron

Question 26

positron symbol

Answer 26

0
β+

1