To find the number of sodium atoms in 100.0 grams of sodium, we need to first calculate the number of moles of sodium in 100.0 grams. We can do this by dividing the mass of sodium by the molar mass of sodium:
$$100.0 \text{ g} / 22.99 \text{ g/mole} = 4.35\text{ moles}$$
Since there are 6.022 x 10^23 atoms in 1 mole of any substance, Avogadro's number, we can multiply the number of moles by Avogadro's number to find the number of sodium atoms in 100.0 grams of sodium:
$$4.35 \text{ mol } * 6.022 \times 10^{23} \text{ atoms/mole} = \boxed{2.62 \times 10^{24} \text{ sodium atoms}}$$
Therefore, there are 2.62 x 10^24 sodium atoms in 100.0 grams of sodium.
