Physics Revision

The number of protons defines the element.

when atoms of the same element have different numbers of neutrons they become an isotope.

mass number = protons+neutrons

atomic number = protons = electrons

alpha = a helium nucleus (two protons and two neutrons)

Beta = high energy electron that is ejected from the nucleus

gamma = high frequency electromagnetic radiation

When particles are deflected, alpha paricles are deflected less than beta particles because they are heavier

Uses of raidiation:

Steralisation - Gamma rays are used to steralise medical equipment and food because they kill bacteria.

Cancer treatment - Gamma radiation can be used to kill cancerous cells. a high dosage is used and the rays are aimed at different angles so that only cancerous cells are killed (can be bad if it kills healthy cells)

Tracers - Tracers are a part of radioactive isotope which is put into a system.

Controlling thickness of materials - as radiation passes through a material some of it is absorbed. the greater the thickness, the greater the absorbtion. this can be used to control thickness of some manufactured materials (e.g. paper)