If the half-life of Sulfate-12 is 18 years, how much of a 6 gram sample is left after 2 half-lives?

The correct answer is - 1/4 0f 6 gram or 1.5 gram to be exact.

Explanation:

Given:

Half-life of sulfate-12 = 18 years

number of half-lives - 2

initial amount - 6 grams.

Solution:

The Half-life of an element or substance is the required time to decay the half amount of the initial amount of the element.

Remaining amount = initial amount * (1/2)^n

here n = number of half lives

then,

Remaining amount = 6* (1/2)^2

= 6/4

= 1.5 g.

Thus, the correct answer is = 1.5 g or 1/4 of 6 gram.