An unknown radioactive substance has a half-life of 3.20 hours . If 16.0 g of the...

An unknown radioactive substance has a half-life of 3.20 hours . If 16.0 g of the substance is currently present, what mass A0 was present 8.00 hours ago?

Expert Solution

no of half lives (n) = total time/half life time

= 8/3.2 = 2.5

The amount of substance left = initial amount/ 2^n

16 = [A0]/2^2.5

[A0] = 16*2^2.5

= 16*5.657 = 90.512g

queen_honey_blossom answered 2 years ago

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