radioactivity

Question 1

radioactive sources emit…

Answer 1

alpha, beta and gamma radiation

Question 2

number of protons is

Answer 2

atomic number

Question 3

total number of protons and neutrons is..

Answer 3

mass number

Question 4

isotopes

Answer 4

same element with different numbers of neutrons

Question 5

relative charge and mass of an alpha particle

Answer 5

mass- 4
charge- +2

Question 6

relative charge and mass of a beta particle

Answer 6

mass- 0
charge- -1

Question 7

gamma ray

Answer 7

electromagnetic wave. no charge or mass

Question 8

ionisation

Answer 8

atoms become positively charged because they lose electrons

Question 9

how does an object become irradiated

Answer 9

exposed to ionising radiation

Question 10

radioactive contamination

Answer 10

unwanted presence of materials containing radioactive atoms on other materials

Question 11

where are alpha radiation stopped

Answer 11

thin sheet of paper

Question 12

where is beta radiation stopped

Answer 12

aluminium

Question 13

where is gamma radiation stopped

Answer 13

lead

Question 14

activity of a radioactive source

Answer 14

number of unstable atoms in the source that decay per second

Question 14

half life is the average time it takes…

Answer 14

for the number of nuclei of the isotope in a sample to halve
for the count rate from the isotope to fall to half of its initial value

Question 14

half life

Answer 14

used to measure how quickly the radioactivity decreases

Question 15

radioactive tracers-

Answer 15

used to measure the flow of a substance through an organ

Question 16

gamma cameras

Answer 16

take pictures on internal organs

Question 17

nuclear fission

Answer 17

splitting of an atomic nucleus into two smaller nuclei

Question 18

fission process results in the emission of

Answer 18

two or three high speed neutrons
energy- in the form of gamma radiation

Question 19

nuclear reactor

Answer 19

the fission process is controlled

Question 20

nuclear fusion

Answer 20

process of forcing two nuclei close enough together so that they form a single larger nucleus

Question 21

nuclear fusion example

Answer 21

process in which energy is released in stars

Question 22

why are high levels of background radiation potentially harmful

Answer 22

as it ionises substances it passes through

Question 23

why is gamma radiation used for tumors

Answer 23

it sends a narrow beam of gamma radiation to destroy cancerous tumors. this is done because it can penetrate deep into your body