1(116 Know that radioactive tleca}r is a change in an tmstahle nucleus that can result in the emission of o: particle or ,8 particles andr'or v radiation and know that these changes are spontaneous and random \"12-? Know that isotopes of an element 1121a}r he radioactive due to an excess of neutrons in the nucleus audio: the nucleus being very heatjr 11212-3 State that during {1 rileca],r or decay: se nucleus changes to that of a different element