In 5.49 s, 1.20g of argon-35 decayed to leave 0.15g. What is the half-life of argon-35?

Answer 1

5.49 seconds is equal to 3 half lifes. Each half life is 1.89 seconds long. In the first half life 1.2 g decayed into 0.6, in the second half life 0.6 g decayed into 0.3 and in the third half life 0.3 g decayed into 0.15 g.

The definition of half life is the amount of time for half to decay.

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