nuclear physics ☢️ Flashcards
What are isotopes
atoms of the same element that have the same proton number but different nucleon number.
What are nucleons
Protons and Neutrons.
What force binds the protons and neutrons together
“Strong Nuclear force”
When does a nucleus disintegrate
When it is unstable
When is a nucleus considered unstable
When the atom has extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable.
What does it mean for nucleus to disintegrate
The nucleus breaks up and radiates a tiny particle in order to achieve stability
What does it mean for a material to be radioactive
The material emits nuclear radiation
What is the meaning of “radioactive decay”
Disintegrations of a heavy nucleus which is random and spontaneous. They can result in the emission of α-particles or β-particles and/or γ-radiation.
What does it mean to have an ionizing effect
Ability to remove electrons from atoms in its path. This makes all the atoms in its path ions
What are the 3 types of radiation
Alpha
Beta
Gamma
What is each radiation stopped by
Alpha - 1 sheet of paper
beta - A sheet of aluminium
gamma - 2 cm or more of lead/thick lead/50 cm of concrete (reduces intensity not fully stop)
Speed of 3 radiations
Alpha - slowest of 3 = 0.1 * c
beta - faster than alpha, slower than gamma = 0.9 * c
gamma - fastest = c
Mass of 3 radiations
Alpha - heaviest
beta - lighter than alpha, heavier than gamma
gamma - none
Relative charges and ionizing powers of 3 radiations
Alpha = +2, strong ionizing
Beta = -1, weak ionizing
gamma = 0, very weak ionizing
Effects of electromagnetic fields on 3 radiation
Alpha and beta - deflected by magnetic and electric fields
Gamma - Not deflected by any fields
What are alpha particles made off
2 protons, 2 neutrons.
Similar structure to nucleus of helium
What are beta particles made off
Each particle is an electron
What are gamma particles made off
Electromagnetic waves similar to X rays
Why are alpha and beta particles deflected in fields
in a magnetic field -
in an electric field -
which gets deflected more in both and which diretion
Alpha beam - flow of positively charged particles (same flow as current)
Beta particles - electrons (flow opp to current)
In a magnetic field - both follow flemings left hand rule
In an electric field - if they pass 2 oppositely charged plates, they experience a force
Beta particles deflected more in both since its lighter but in the opposite direction to alpha particles since charges are opposite
how can the deflection of alpha and beta rays in magnetic fields be found?
alpha particles are heavy and a flow of positively charged particles, so it is equivalent to an electric current, hence we can use Flemings’ left-hand rule to find the direction of deflection. As it is heavy it is deflected less
(since its positive, its the same direction as conventional current hence alpha is left hand rule and beta is the opp of wtv alpa is)
beta particles are much lighter and are a flow of negatively charged particles so it is equivalent to an electron flowing in a magnetic field, which is the opposite direction of the current flow. As it is light it deflects more
background radiation definition
Background radiation is the radiation that is present all around in the environment
what are the factors that make a significant contribution to background radiation
radon gas (in the air)
rocks and buildings
food and drink
cosmic rays
how is a Geiger muller tube used to detect alpha particles
if an alpha particle enters the tube, sparks are produced towards the negative plate and a big and loud sound is created
how is a Geiger muller tube used to detect beta particles
if a beta particle enters the tube, sparks are produced towards the positive plate, this spark is fast and a low sound is produced
