The half-life of tritium, or hydrogen-3, is 12.32 years. after about 37 years, how much of a sample of tritium will remain unchanged?

a. 1/3
b.1/8
c.1/16
d.1/2

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?

How does kepler second law of planetary motion overthrow one of the basic beliefs of classical astronomy