Number of half life decayed, atoms that remained were
First half life = ½ (1.0 x 10^20)
Second half life = ½ ( ½ x1.0 x 10^20)
Third half life = ½ ( ½ x ½ x 1.0 x 10^20)
= 1/8 x 10^20
Thus atoms decayed = 1.0 x 10^20 – 0.125 x10^20
=0.875 x 10^20
=8.75 x 10^19
joseph rimiru answered the question on December 11, 2017 at 18:06
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