Radioactivity

Question 1

Irradiation

Answer 1

lasts for a short period of time

the source emits radiation,

Question 2

Contamination

Answer 2

lasts for a long period of time

source of radiation is transferred to an object

Question 3

Uses of radioactivity

Answer 3

smoke alarms-

irritating food-

treatment of cancer-

Tracing

Question 4

Half life

Answer 4

is the time taken for half the nuclei in a sample to decay

Question 5

Decay processes

Answer 5

Beta-minus decay

beta-plus decay

Question 6

Atomic structure

Answer 6

1800- Dalton said everything was made of atoms

1897- J.J Thomson discovered the electron

1911- Rutherford realised most of the atom was from empty space

1913- Niels Bohr produced the final model of the atom

Question 7

Methods of measuring radioactivity

Answer 7

Photographic film

Geiger-muller tube

Question 8

Examples of background radiation

Answer 8

cosmic rays

nuclear fallout

Medical rays

Question 9

Background radiation

Answer 9

weak radiation that can be detected from natural/ external sources

Question 10

Beta plus (positron)

Answer 10

medium ionising

medium penetration

Question 11

Beta minus (electron)

Answer 11

medium ionising

medium penetration

Question 12

Alpha (A helium nucleus)

Answer 12

highly ionising

weakly penetrating

Question 13

Radiation

Answer 13

decay occurs in a random process

forms of decay

Question 14

isotopes and elements

Answer 14

atoms of the same element have the same number of protons

Neutral atoms have the same number of electrons and protons

isotopes are atoms of the same element, but with different masses

Question 15

Subatomic particle

Answer 15

proton relative mass- 1 - relative charge +1

Neutron relative mass- 1 relative charge- 0

Electron relative mass- 0.0005 relative charge- 1

positron relative mass- 0.0005 relative charge +1

Question 16

Atom

Answer 16

positively charged nucleus

made of positive atoms

and neutral atoms