Answer:- C. Hafnium.
Solution:- Mass of the sample is 46.0 g and it's volume is
.
From mass and volume, we can calculate it's density using the formula:



On the basis of the density, this substance could either be mercury or hafnium. Since the substance is a solid at room temperature where as mercury is liquid. So, it can't be mercury.
The right choice is C) Hafnium.
Answer:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic.
Explanation:
A metallic bond is a force that holds atoms together in a metallic substance.
A physical change. chemical changes require the molecule itself to change. If you put NaCl into solution, the NaCl is still there which is evident by the fact that if you lower the amount of water, NaCl precipitates out.