Radioactivity

Created by

vic

Cards (28)

What symbol is used when referring to the mass number? 
A - this symbol refers to the number of protons and neutrons
What symbol is used to refer to the atomic number? 
Z - this symbol refers to protons only (bottom number)
How would you determine the amount of neutrons in an element? 
PEN - (A-Z) (Top number minus the bottom)
What are the three isotopes of hydrogen?
Protium - 1H
Deutrium - 2H
Tritirum - 3H
Define an isotope 
An isotope is an atom of the same element that has the same number of protons but different number neutrons.
What does it mean if something is radioactive? 
If an atom is radioactive it means it emits ionising radiation or particles
When is the nucleus considered stable?
When the binding energy (which holds together protons and neutrons in the nucleus) is strong enough the nucleus is considered stable - when the binding energy is not strong enough, the nucleus is unstable!
What will unstable atoms do? 
Unstable atoms of certain isotopes will lose mass and energy in order to become stable - to do this the atom releases radiation in the form of alpha, beta and gamma radiation
Define an alpha particle 
An alpha particle consists of 2 protons and 2 neutrons ( meaning it is essentially a helium nucleus as they both have mass numbers of 4)
What are the mass and charge properties of an alpha particle? 
An alpha particles relative mass is 4 - and relative charge is 2+
Define beta radiation 
A beta particle consists of a fast moving electron - emitted when a neutron in the nucleus turns into a proton
What are the mass and charge properties of a beta particle? 
A beta particles relative mass is 0 - and relative charge is -1
Define gamma radiation 
Gamma radiation is a high energy, high frequency WAVE with a very short wavelength!
What are the mass and charge properties of gamma radiation? 
Gamma radiation has no mass and no charge as it is a wave!
What is a particles penetrating power? 
A particles penetrating power is referring to the distance its waves/particles can penetrate through air or an object!
Order the three types of radiation based on their penetrating power 
WEAKEST - alpha
- beta
STRONGEST - gamma
Describe an alpha particles penetrating power 
Alpha radiation has the LEAST penetrating power as they are heavy particles - it can be stopped by a thin piece of paper - its range in air is 5 cm
Describe a beta particles penetrating power 
Beta radiation can travel a few metres through air ( and a thin sheet of paper ) but is stopped by a thin sheet of aluminium - its range in air is 1m
Describe the penetrating power of gamma particles 
Gamma radiation has the most penetrating power - and the highest frequency - gamma requires lead or 1m thick concrete to be stopped - its range in air theoretically is unlimited
What is meant by 'ionising power'? 
This refers to the different types of radiations ability to cause other atoms to loose electrons - therefore forming an ion (picture a wrecking ball, going past particles taking electrons from them - ionising them)
Order the three types of radiation in terms of Ionising power 
WEAKEST - gamma
-beta
STRONGEST -alpha
Describe in terms of charge the reasoning for the order of ionising power 
Alpha particles have the largest charge (2+) and so ionises atoms easily as it passes them
Beta particles have smaller charges than alpha and so moderately ionises atoms as they pass them
Gamma is the least ionising radiation as it does not interact with atoms as much when it passes! (wave)
What is the notation for alpha decay? 
(in terms of A and Z)
During alpha decay - how much does A reduce by? 
A - 4 (the mass number is decreased by 4)
During alpha decay - how much does Z decrease by? 
Z-2 (the atomic number decreases by two!)
What is the notation of beta decay equations? 
(in terms of A and Z)
During beta decay - by how much does A increase/decrease by? 
Nothing - A stays the same!
During beta decay - how much does Z increase/decrease by? 
Z+1 (the atomic number increases by 1)