Radioactivity-notes
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An atomic model has 2 electrons in the outer shell, 2 neutrons, 2 protons
Proton and neutrons have a relative mass of 1 and electron is 1/2000
Isotope- same elements with different neutrons numbers
Electrons=neutrons
Radioactive= the emission of radiation in the form of particles or high energy protons
resulting from a nuclear reaction
 Ionisation= the addition or removal of an electron to create an ion
Types of radiation
 an unstable nucleus can decay by emitting three types of particles
 Alpha= if nucleus has too few neutrons, it will emit 2 protons and 2 neutrons, it causes
the mass number to decrease by 4 and the atomic number to decrease by 2
 Beta= if the nucleus has too many neutrons it emits a fast-moving electron (beta). This
causes the atomic number to increase by one and the mass number to remain the
same
 Gamma= energy levels in the nucleus are higher than the gas so the nucleus will cool
down by emitting a wavelength called gamma ray, no change in the numbers