History:
Strontium was discovered in 1789 by English scientist Dr Adair Crawford in a Scottish village called Strontian and recognized it was different from barium minerals.

Properties:
Strontium  is a silvery white element            in group 2 the alkali earth metals in the periodic table just below calcium. Strontium behaves the same way as calcium however it is softer. Like all alkali earth metals Strontium has 2 valence electrons so it is more likely to react with any element from the oxygen family which have 6 valence electrons. Strontium tarnishes and burns spontaneously when exposed to air. Strontium is a good electric conductor.           

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Isotopes:
Strontiums 84,86,87, 88,90 and 97. Strontium 88,90 and 97 are its radioactive isotopes. Strontium 90 is used in nuclear bomb testings and it can contaminate large areas after it has dropped down from  the atmosphere. Plants absorb the strontium 90 and when cows and other domestic animals eat the plants they also take the strontium 90. Also when Because it behaves the same way as calcium strontium 90 it enters the bones and teeth. Since it’s a radioactive element strontium 90 gives off radiation and kills living cells in the bone marrow and because its half life is 28.8 years it will stay in your body for 57.6 years.  Operators of nuclear reactors must be aware of strontium 90 being released into the enviroment. The other radioactive element strontium 97 only has a half life of 2.8 hours so it can be eliminated from the body so radiation is kept to a minimum.Strontium 87 is injected into a patients body and is taken up bone tissue. Radiation detectors are used to locate the strontium in the patients body. Doctors use strontium 87 to replace calcium.