2. Atoms & Elements

In the context of the mole concept, how many particles (atoms, molecules, or ions) are present in one mole of any element or compound?

How many moles are present in 3.55 × 10^{22} formula units of NaCl?

One mole of particles of any substance contains how many particles?

If you produced 5 moles of Ca3(PO4)2, how many moles of calcium ions (Ca^{2+}) are present?

How many molecules are present in 3.6 grams of NaCl?

How many moles are present in 2.5 g of N_2?

How many moles of nitrogen atoms (N) are present in 0.207 g of N_2O?

What is the total number of atoms contained in a 1.00-mole sample of helium (He)?

How many moles of MgCO_3 are present in 252.939 grams of MgCO_3?

How many moles of chlorine gas (Cl_2) are contained in 9.02 × 10^{23} molecules?

How many water molecules are present in 5.2 moles of H_2O?

In chemistry, what does a mole represent?

Which of the following samples contains the greatest number of moles?

How many moles are present in 17.5 grams of sodium (Na)? (Atomic mass of Na = 23.0 g/mol)

Which proportionality correctly describes Avogadro's law?