Archaeologists and historians have determined that ancient nubia had a rich trade relationship with ancient egypt. which answer provides the best evidence of this?
a.
many egyptian artifacts were made of goods that came from nubia.
b.
the ruler of nubia was called a pharaoh, just like the ruler of egypt.
c.
egypt and nubia usually allied together to conquer their enemies.
d.
nubia and egypt both had contact with many different cultural groups.

Hypothesis:

The amount of limestone that dissolves in the acid is directly proportional to the concentration of acid used.

Explanation:

Acids dissolve limestone according to the following general equation;

2HX(aq) + CaCO3(s) > CaX2(aq) + H2O (l) + CO2(g). Where HX represents any acid at all.

This dissolution process is a chemical reaction. It was experimentally observed that the amount of limestone that dissolved in acid depends on the concentration of acid. Various concentrations of acid were then prepared and a particular mass of limestone was dissolved in each concentration of acid. The amount of limestone dissolved in each case was carefully noted.

It was observed that as the concentration of acid increased, the amount of limestone dissolved increased also and vice versa, hence the hypothesis proposed above.