What is the difference between alpha and gamma radiation?

Alpha radiation is a type of radiaiton which has a high ionisation and low penetration. This means it can ionise objects very easily (so can be more damaging to humans) but it can only travel a very short distance (a few cm in air). Alpha radiaiton is produced from a large atomic nucleus by the equation: (x,y)Z => (x-4,y-2)P + (4,2)He. The second product (the helium nucleus) is an alpha particle and what alpha radiation is.In comparison gamma radiation is a type of electromagnetic wave and has a low ionisation but a high penetration (opposite to alpha!). This means gamma radiation is less ionising so more safe to humans and also it can travel very far. It would take a few metres of concrete or a few cm of lead to stop it.