GCSE WJEC Physics- radiation

isotope definition

same element + protons diff neutrons

what is background radiation

low level of radiation

how radon enters house + prevention

cracks

artificial background radiation

medicine + nuclear

why are elements radioactive

due to an imbalance between no. of protons + neutrons in nucleus

ionization defintion

gaining or losing electrons

radon variation by area reason

rocks → diff amount in diff places

unit of radioactivity

becquerel (Bq)

1 Bq is equivalent to

1 radioactive decay per second

particles that make up nucleus

proton + neutron

half life definition

time taken for half the radioactive nucleii to decay OR drop to half the original radiation level

element decayed by beta emission what happens

mass stays same + atomic up by 1

how to reduce radioactive decay random effects

1) repeat experiment + calculate average

2) carry out experiment over longer period of time

element decayed by alpha emission what happens

mass down 4 + atomic down 2

alpha penetrating distance

low- absorbed by paper/ skin

beta penetrating distance

medium- absorbed by thin sheet of aluminium

gamma penetrating distance

high- reduced by thick lead

most dangerous radiation inside body

alpha

most dangerous radiation outside body

gamma

alpha particles charge

+

radiation biological effect

can cause cell mutation which can cause cancer

beta particles charge

-

gamma rays charge

0

gamma rays nature

electromagnetic wave

natural background radiation

-radon

-food

-cosmic rays

beta particles nature

high energy electron

alpha particles nature

helium nucleus (2 protons + 2 neutrons)

Radiation danger outside of body

alpha presents no danger + beta and gamma can get into body + beta is more ionising so more dangerous

A + D nuclear waste disposal storage underwater  

A- well away from human activity + D- possible leakage in long term