What number of atoms are in 3.89 mols of No2? 

To determine the number of atoms in 3.89 moles of , we start by calculating the number of molecules present. Using Avogadro’s number, which is approximately molecules per mole, we multiply this by the number of moles:

\text{Number of molecules} = 3.89 \, \text{mol} \times 6.022 \times 10^{23} \, \text{molecules/mol} \approx 2.34 \times 10^{24} \, \text{molecules}

Next, we recognize that each molecule of consists of three atoms: one nitrogen atom and two oxygen atoms. Therefore, to find the total number of atoms, we multiply the total number of molecules by the number of atoms per molecule:

\text{Total atoms} = \text{Number of molecules} \times 3 = 2.34 \times 10^{24} \, \text{molecules} \times 3 \approx 7.02 \times 10^{24} \, \text{atoms}

In conclusion, there are approximately atoms in 3.89 moles of . This calculation underscores the vast number of atoms present even in relatively small amounts of a substance, reflecting the scale of atomic and molecular quantities in chemistry.