Radioactivity
-  Natural radioactivity was discovered by
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                        View Hint View Answer Discuss in Forum Natural Radio activity was discovered by Becquerel. Correct Option: BNatural Radio activity was discovered by Becquerel. 
-  A radioactive substance emits
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                        View Hint View Answer Discuss in Forum A radioactive substance emits alpha, beta and gamma particles. Correct Option: DA radioactive substance emits alpha, beta and gamma particles. 
-  A device used for the measurement of radioactivity is
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                        View Hint View Answer Discuss in Forum G.M. counter is a device used for the measurement of radioactivity. Correct Option: DG.M. counter is a device used for the measurement of radioactivity. 
-  A radioactive substance has a half life of four months. Three - fourth of the substance would decay in
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                        View Hint View Answer Discuss in Forum Given half life (t1/2) = 4 months 
 Hence the amount of a radioactive substance remains half after 4 months. Hence, 3/4th of a substance would decay in two half lives i.e., 8 months.Correct Option: CGiven half life (t1/2) = 4 months 
 Hence the amount of a radioactive substance remains half after 4 months. Hence, 3/4th of a substance would decay in two half lives i.e., 8 months.
 
	