The half-life of radium is about `1600 yr`. Of `100g` of radium existing now, `25 g` will remain unchanged afterA. 6400 yearsB. 2400 yearsC. 3200 yearsD. 4800 years

The half-life of radium is about `1600 yr`. Of `100g` of radium existi

1.	The half-life of radium is about `1600 yr`. Of `100g` of radium existing now, `25 g` will remain unchanged afterA. 6400 yearsB. 2400 yearsC. 3200 yearsD. 4800 years
Answer» Correct Answer - C `{:(M_0=100g,"(initial mass )"),("M=25g","(active mass)"):}}rArrN_0/N=100/25` `Delta=2^2rArr n=2` Therefore required time =`2xxT_(1//2)`=3200 yrs

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The half-life of radium is about `1600 yr`. Of `100g` of radium existing now, `25 g` will remain unchanged afterA. 6400 yearsB. 2400 yearsC. 3200 yearsD. 4800 years

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