Chapter 7 - Radioactivity and Particles Flashcards
Edexcel iGCSE Physics (19 cards)
why do atoms become nuclear
their nuclei become unstable due to an unbalanced number of protons and neutrons and therefore radioactive
what is the process of emitting radiation called?
radioactive decay
what are the three types of radiation emitted by nuclei?
Alpha, Beta, Gamma
what is alpha radiation made of
two neutrons, two protons
What is beta radiation made of?
A high energy electron -> the spare neutron turns into a proton and an electron
what is Gamma radiation made of?
it is an electromagnetic wave
what can be used to stop alpha particles from penetrating?
paper
what can be used to stop beta particles from penetrating?
a few mm of aluminium
what can be used to stop Gamma radiation from penetrating?
thick lead
how is radiation recorded?
using a Geiger-muller tube
what makes up background radiation?
50% radon gas, 15% rocks and building materials, 15% medical (xrays), 11% food, 10% cosmic rays, 1% other
does a half life graph ever touch zero activity?
NO!
what are the uses of radiation?
Smoke detectors, measuring the thickness of materials, diagnosis and cancer treatment, sterilising food and medical equipment
what does it mean if something is irradiated?
Occurs when an object is exposed to a source of radiation outside the object.
what does it mean if something is contaminated?
Occurs if the radioactive source is on or in the object.
what can be worn to protect against radiation?
- lead clothing i.e. gloves
- radiation suit
how would you store alpha emitting sources?
in a plastic or metal container
how would you store beta emitting sources?
in aluminium canisters/ silos
how would you store gamma emitting sources?
in a thick lead lined concrete silo
