1. True or False Alpha is the least penetrating form of radiation
Betas particles are radioactive
Up and Down are antimatter pairs of quarks
Gamma is a highly penetrating form of radiation
The radioactive sources in school are safe to use because they have a short half life.
Alpha decay will increase the proton number by 2.
A particle formed by beta+ emission will have a lepton number of 1.
All hadrons consist of 3 quarks
Only quarks are influenced by the nuclear strong force
Marie Curie discovered radioactivity

2. A graph can be plotted showing the change in N, the
N – Z Curves
A graph can be plotted showing all known nuclides with N, the neutron number, plotted against Z, the proton number.
This produces a graph which has a thin line of stable elements with a non-linear gradient slightly steeper than 1.0 (i.e. 1 proton for each neutron).
We know this will be the case because the repulsive force experienced by the protons would be too great if the neutrons were not there to separate them.
Each additional neutron increases the nuclear strong force whilst lessening the electrostatic repulsion due to separation of charges.

3. Z>83 Too many protons and neutrons: α emission
Stable nuclei line
Too many neutrons to be stable: β- emission
Too many protons to be stable: β+ emission

6. Empirical rules deduced from the N – Z curve
Lighter nuclides (Z < 20) have N approximately equal to Z
Heavier nuclides require more neutrons than protons to be stable
For all values of Z > 83, nuclei are unstable
Most stable nuclei have even numbers of protons and neutrons

7. 2 neutrons and 2 protons are given out
What does an alpha decay look like on the N – Z graph? N
Neutron no.
Proton no. Z
Alpha:
2 neutrons and 2 protons are given out

8. A neutron turns into a proton
What does beta decay look like on the N – Z graph? N
Neutron no.
Proton no. Z
Beta:
A neutron turns into a proton

9. U - 238 will decay through a process of alpha and beta decays to form the stable isotope Pb - 206.
Can you work out the decay chain?

10. U-238 DECAY CHAIN

11. gamma
absorption
emission
penetration
stable
alpha
unstable
decay
nucleus
beta