Fermium-253 has a half life of 3 days. What percent of the sample is still Fermium-253 after 15 days?

.

Explanation:

After every half-life, the quantity of the sample will become of the quantity at the beginning of the half-life. If the half-life for Fermium-253 is 3 days, it can be deduced that:

.

Let . In general, after half-lives (for the fermium-253 in this question, that would be days,) the percentage of the sample that's still the initial substance would be:

.

There are half lives in 15 days. (In other words, .) Therefore, the percentage of this sample that's still fermium-253 would be:

.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: