D. radioactive isotopes are one of the environmental waste products of nuclear energy.
The answer for this question is niche.
Answer:
112.2L
Explanation:
Volume (V) = 300g
Temperature (T) = 822K
Pressure (P) = 0.9atm
using the ideal gas equation;

Molar gas constant (R) = 
Mole (n) =
Molar mass of Mercury = 200.59g/mol

= 1.496mol
Now, the volume can be calculated;
V = 
∴Volume of mercury = 
The mass number of an isotope can be expressed <span>by simply writing the name of the element or symbol followed by a hyphen and the mass number.
Example:
Carbon-13, Carbon-14
Oxygen-17
Uranium-235
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