. 2. Which has more atoms: 2.5 mol of calcium carbonate, CaCO3, or 3.5 mol of calcium hydroxide, Ca(OH)2

Calcium hydroxide has more atoms.

Explanation:

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

Then you can apply the following rules of three:

amount of moles of calcium carbonate= 1.50575*10²⁴

amount of moles of calcium hydroxide= 2.10805*10²⁴

2.10805*10²⁴ is greater is 1.50575*10²⁴, so calcium hydroxide has more atoms.

b) nuclear ive learned that in a pedtrodic table