I am rather confused by how the significant figure is suppose to work when you have logarithms in your equation. For example:(adsbygoogle = window.adsbygoogle || []).push({});

Francium-87 undergoes beta decay with a half life of 22 min. How much of a 15.00 grams sample remains after 2.0 hours?

Well, I used this equation:

[tex]logA =log 15.00g-\frac{0.301(2.0hours)}{22minutes}[/tex]

After solving it, i get:

logA = -0.4 --> A = 10^-0.4

And arrived at an answer of 0.4g

This is where i get confused, noticed the bold prints. Am i suppose to round my answers to the sig figs based on the first 1 or the second 1?

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# Log Sig Figs Confusion

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