6 The half-life of carbon-14 is 5,700 years. A sample of wood that originally contained 100 grams of carbon-14 now contains only 25 grams of carbon-14. Approximately how many years ago was this sample part of a living tree? * (6 Points)​

The correct answer is - 10400 years.

Explanation:

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

Here, the initial amount n(i) = 100 gm

remained amount n(r) = 25 gm

then n =?

The formula for the calculating initial amount

n(i)=n(r)⋅2^n

n(i)=n(r)⋅2^n

n(i)/n(r) =2^n

puting value,

100/25 = 2^n

2^n = 4

n = 2

so to decay this amount there is two half life cycles involved,

Thus, time = 2*5700

= 10400 years.

the maximum mass of nh3 is nh3 in grams

the right answer is c i just did the question.