For radioactive decay, we can relate current amount, initial amount, decay constant and time using:
N = No x exp(-λt)
Half-life = ln(2)/λ
λ = ln(2) / 5730
N/No = 80% = 0.8
0.8 = exp( -ln(2)/5730 x t)
t = 1844 years
Answer:
40%
Explanation:
Calculate the percent of the mass that is carbon:

The outermost energy shell of an atom
because they are involved in forming bonds
<span>The amount of dissolved salt in the liquid sample is measured and reported as salinity. The salinity is usually measured in parts per thousand (ppt). The salinity of ocean averages 35 ppt while that of the river averages 0.5 ppt or less. In other terms, the word salinity is the saltiness. </span>