Radioactivity Flashcards
the nuclei in most atoms are said to be…
stable
in some atoms the protons and neutrons are…
and these nucleis are…
not held togther
unstable
what are radioisotopes?
isotopes that are unstable decay which form elements and are said to be radioactive
how are artifically made isotopes made?
by bombarding their atoms with protons or neutrons
what is nucleus radation?
energy emitted by radioactive subtances
what are the three types of radation?
alpha particles
beta particles
gamma rays
what are alpha particles?
helium nuclei that contains 2 protons and 2 neutrons
what is the charge of alpha particles?
positive
what is the symbol for alpha particles?
a
what are some of the properties of alpha particles?
they cannot travel easily through materials
they can be stopped by paper or skin
can cause serious damage if inhaled , eaten or injected
what is the symbol for beta particles?
β
what are beta particles the same size and mass of?
electrons
what charge are beta particles?
positive or negative
what is a negative charge particles called?
negatron
what is a positive charge particles called?
positron
how fast can beta particles travel?
99% speed of light
what are some properties of beta particles?
can penetrate human skin and damage living tissue
cannot penetrate think layers of plastic, wood or aluminium
what are gamma rays not?
not particles
what are gamma rays?
bursts of energy that are realsed after alpha or beta particles are emitted
what speed do they travel?
speed of light
what is the symbol of gamma rays?
γ
gamma rays cannot be stopped by…
thick sheild of lead or concrete
what is a property or gamma rays?
cause serious and permant damage to living tissue
order of ionising power?
alpha, beta and gamma
order of high pentarting power?
gamma, beta and alpha
what is the process of radioactive decay?
when the ratio of neutrons to protons become too high and the nucleus is unstable and decays or changes into another isotope
radioactive decay is a…
random process
what is half life?
is the time taken for half of the radioactive nuclei in a sample to decay
what is half life equivalent too?
the time taken for the radioactivty to drop half of what it was
what is cosmic radiation?
a smaller amount that comes from outer space in a form of high energy protons emitted by stars
