Answer:
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:
[tex]amount of moles of calcium carbonate=\frac{2.5 moles*6.023*10^{23} atoms}{1 mole}[/tex]
amount of moles of calcium carbonate= 1.50575*10²⁴
[tex]amount of moles of calcium hydroxide=\frac{3.5 moles*6.023*10^{23} atoms}{1 mole}[/tex]
amount of moles of calcium hydroxide= 2.10805*10²⁴
2.10805*10²⁴ is greater is 1.50575*10²⁴, so calcium hydroxide has more atoms.