A substance known as heavy water can be
obtained from ordinary water and could be a significant
source of energy in the future. Heavy water contains
deuterium, H-2. Instead of the two hydrogen atoms in a
typical water molecule, a heavy water molecule has two
deuterium atoms. In 3.78 kilograms of ordinary water, the
percent composition by mass of heavy water is approximately
0.0156%. Deuterium atoms completely ionize at approximately
10^{8 }K. The
result is an ionized gas consisting of electrons and
deuterons (the nuclei of deuterium). A triton is the nucleus
of a tritium atom, H-3. These particles react according to
the equations below. In the second equation,
*X *
represents an unidentified product.

78 Calculate the mass of heavy water in a
3.78-kilogram sample of ordinary water. Your response must
include *both
*a correct numerical setup and the calculated
result. [2]

**HIGHLIGHT TO SEE THE ANSWER**

(0.000
156)(3.78 kg)
Answer==>0.000 590kg
or 5.90
x 10^{-4}kg |

79 Identify particle
*X *in
the second nuclear equation. Your response must include the
symbol, atomic number, and mass number of the particle. [1]

**HIGHLIGHT TO SEE THE ANSWER**