RADIOACTIVITY

 Radioactivity

• Know the relative masses and relative electric charges

  of protons, neutrons and electrons.

• In an atom, number of electrons = number of protons

 in the nucleus. The atom has zero net electrical charge.










• Atoms may lose or gain electrons to form ions.

• Atoms of a particular element have the same number of protons.

• Atoms of different elements have different numbers of protons.

• Atoms of the same element which have different

 numbers of neutrons are called isotopes.

• The number of protons is called the atomic number.

• The number of protons and neutrons is called the mass number.

• Know the effect of a and ß decay on radioactive nuclei.

• Know the origins of background radiation