physics revision particle model of matter Flashcards
what is radioactive decay
when a nuclei is unstable and begins to emits radiation
why do radiactive substances not last forever
radioactive decay
what is alpha made of
2 protons and 2 neutrons like helium
what is beta
fast moving electron with -1 charge
how is gamma different
it is a wave with no charge
what is an ion
atom that has become charged
what 2 things do ionisation cause
tissue damage and
possible dna mutation
what is activity
nuclear decays per second
why is alpha most ionising
has the strongest pos charge so will attract electrons
makes atom ion
how does beta ionise
repels electrons which could leave atom
what stops beta
and
and alpha
beta-thin aluminium sheet
alpha-few cm in air
order penetrative power of radiation
gamma
beta
alpha
how can gamma be partially stopped
by thick lead or cement
order ionising power of radiation
alpha
beta
gamma
order of radiation speed
same as penetrative
how can 3 ways we reduce damage to bodies by radioactive substances
wear protective clothing
work in cabinet
keep in lead lined container
What sub atomic particles most likely have unstable nuclei
isotopes
