GCSE 2 - Radioactivity Flashcards
Why does an atom give off radiation?
To stabilise its nucleus.
What does an imbalance of protons and neutrons cause?
Unstable nuclei which leads to radioactive decay.
What are the three forms of radioactive decay?
Alpha radiation - Helium nuclei
Beta radiation - Fast moving electron
Gamma radiation - Electromagnetic wave
What are the properties of alpha radiation?
They are helium nuclei (2 protons, 2 neutrons)
They have a positive charge +2
Very ionising
Not penetrative - stopped by air and paper
What are the properties of Beta radiation?
They are fast moving electrons
Negative charge -1
Fairly ionising
Fairly penetrative - stopped by aluminium
What are the properties of gamma radiation?
It is an electromagnetic wave
Has no charge
Not very ionising
Very penetrative - stopped by lead
How do you measure radioactivity?
A Geiger Counter measures radioactivity in counts per minutes or Becquerels
How do you fill out a radioactive equation?
Atomic numbers before and after have the same total, as do the mass numbers
What is a half life?
The time taken for the radioactive substance to decrease by half
Why can we not perform fusion of Earth?
It requires high temperatures and pressures which are not safe and are unable to be contained
How does the sun produce its energy?
The fusion of two hydrogen isotopes into a helium atom and a neutron
