Answer
A. molecules
Explanation
When atoms or elements combine, they are called molecules. When molecules combine they form compounds.
Answer: Option (b) is the correct answer.
Explanation:
Compressibility means the ability to reduce or compress in size.
In solids, molecules are held together by strong force of attraction. Therefore, it requires very high force or energy to break the bond between the molecules of a solid.
As a result, compressibility of solids is low.
Whereas a hot ionized gas which contains same number of both positive or negatively charged electrons is known as plasma. Being a gas, molecules of plasma are not held by strong force of attractions.
Hence, plasma is compressible as compared to solids.
Thus, we can conclude that out of the given options, the statement compressibility of solids is lower than the compressibility of plasmas and gases is true.
The independent variable is the one we are changing in the experiment. As we change it, the dependent variable might also change.
C. the density of the rock because we are changing the density of the rock and seeing how all other variables change with regards to the density.
C & B are switched so I'm not sure if that was a typo or not, but the answer is concentration!