Find the answers to the following questions: 1. How many moles are there in 1.204 x 1024 molecules of water (H2O)? 2. Calculate the number of moles in 3.011 x 1022 atoms of helium (He). 3. If you have 5.000 x 1023 molecules of carbon dioxide (CO2), how many moles do you have?

Number of molecules ($N$) $= 1.204 \times 10^{24}$ molecules.
Avogadro's number ($N_A$) $= 6.022 \times 10^{23}$ molecules/mol.

Rounding to three significant figures:

The number of moles is $\boxed{\text{2.00 mol}}$.

2) Calculate the number of moles in $3.011 \times 10^{22}$ atoms of helium ($\text{He}$).

Number of atoms ($N$) $= 3.011 \times 10^{22}$ atoms.
Avogadro's number ($N_A$) $= 6.022 \times 10^{23}$ atoms/mol.

Rounding to three significant figures:

The number of moles is $\boxed{\text{0.0500 mol}}$.

3) If you have $5.000 \times 10^{23}$ molecules of carbon dioxide ($\text{CO}_2$), how many moles do you have?

Number of molecules ($N$) $= 5.000 \times 10^{23}$ molecules.
Avogadro's number ($N_A$) $= 6.022 \times 10^{23}$ molecules/mol.

Rounding to four significant figures:

The number of moles is $\boxed{\text{0.8303 mol}}$.