It's A. volume
Pressure =

with const depends on the chosen unit of volume
I think so...
Answer
The second part of the theory says all atoms of a given element are identical in mass and properties. The third part says compounds are combinations of two or more different types of atoms. The fourth part of the theory states that a chemical reaction is a rearrangement of atoms.
Explanation:
Because a copper ion looses electrons, meaning it's negatively charged, and positives and negatives attract.
True,I think.(so don't really count on my answer sorry :D)
Answer: Solubility
Explanation:
Solubility is the ability or property of a solute which can be a solid, liquid, or gaseous chemical substance to dissolve in a solvent (solid, liquid or gas) and form a solution. The factors that affect how soluble a substance is depends on the solvent ,temperature and pressure.
Here, Mario trying to dissolve certain substances (solutes) in water (the solvent shows he is trying to find out the solubility of the substances which can be insoluble, sparingly soluble or very soluble.