Isotopes and Nuclear Radiation + Nuclear Equations Flashcards
what is a isotope
atoms with the same number of protons, but different number of neurons
which subatomic particle determines the element
protons
what does the atomic number represent
number of protons
what does the mass number show
number of protons + neutrons
what is the process of radioactive decay
when unstable nuclei decay into other elements and give out radiation as they try to become more stable
what are Alpha particles
Helium Nuclei - 2 neutrons + 2 protons
what can alpha particles be stopped by
- 5 cm of air
- thin sheet of paper
what is ionising radiation
radiation that knocks electrons off atoms, creating positive ions
how is alpha radiation used in smoke detectors
- it ionises air particles cuasing a current to flow
- if smoke in air - it binds to ions - breaks circuit current flow
- alarm sounds
is alpha strongly or weakly ionising and what is the effect
Strongly ionising = travels the least distance
why are alpha particles strongly ionising
- large size
- strong charge 2+
what is a beta particle
a fast moving electron released by the nucleus
what is the mass and charge of a beta particle
- virtually no mass
- charge = -1
what level of ionising is beta and what is the effect
moderately ionising –> penetrate moderately far into materials before colliding
what can stop beta radiation
- aluminium sheet - 5mm
- 1m of air
what happens to the atom during beta decay
- neutron decays into proton + electron
- protons stays in nucleus
- electron is emitted out
what happens to the atomic number, mass and charge of a atom after beta radiation
- atomic number - +1
- mass - unchanged
- charge - 1+
what is gamma rays
electromagnetic radiation released by the nucleus
are gamma rays strong or weakly ionising and what is the effect
weakly ionising = penetrate far + travel long distances in air
what is gamma rays range in air
unlimited - spread out without being absorbed
what materials can stop gamma radiation
- Thick lead sheet - several cm
- concrete - >1m
what can beta radiation be used for
beta emitter used to **test thickness of metal sheets*
- as particles are not absorbed by material like alpha
- do not penetrate as far as gamma
what are Irradiated objects
not radioactive but have been exposed to ionising radiation
what are contaminated objects
have an unwanted presence of radioactive materials on them –> will emit radiation
when an atom emits a alpha particle what happens to it atomic and mass number
Atomic - reduces by 2
Mass - reduces by 4
