Its an element Im pretty sure
The amount of energy required to change the temperature or phase of a reactant
Answer: A. the rotational period of the earth is the same as that of the moon
Density is defined as mass/volume (or m/v).
So,
(126.0 g)/(12.5 cm^3)= 10.08 g/cm^3
If your teacher requires correct significant figures, the answer is 10.1 g/cm^3.
If not, the first answer is fine.
