* Limestone is a compound: It's primarily made of calcium carbonate (CaCO3).
* Each molecule has a fixed number of atoms: One molecule of calcium carbonate has 1 calcium atom, 1 carbon atom, and 3 oxygen atoms (total of 5 atoms).
* Limestone samples vary in size: A small piece of limestone will have fewer molecules (and therefore fewer atoms) than a large boulder.
To calculate the number of atoms in a specific sample of limestone:
1. Determine the mass of the limestone sample.
2. Find the molar mass of calcium carbonate (CaCO3): This is approximately 100 g/mol.
3. Calculate the number of moles of CaCO3 in your sample: Divide the mass of your sample by the molar mass of CaCO3.
4. Multiply the number of moles by Avogadro's number (6.022 x 10^23 molecules/mol): This gives you the number of CaCO3 molecules in your sample.
5. Multiply the number of molecules by 5: Since each CaCO3 molecule has 5 atoms, this gives you the total number of atoms in your sample.
Example:
Let's say you have a 50 gram sample of limestone.
1. Mass = 50 g
2. Molar mass of CaCO3 = 100 g/mol
3. Moles of CaCO3 = 50 g / 100 g/mol = 0.5 mol
4. Number of molecules = 0.5 mol * 6.022 x 10^23 molecules/mol = 3.011 x 10^23 molecules
5. Number of atoms = 3.011 x 10^23 molecules * 5 atoms/molecule = 1.5055 x 10^24 atoms
Therefore, a 50-gram sample of limestone would contain approximately 1.5055 x 10^24 atoms.
