Final answer:
To determine which sample contains the greatest number of atoms, we calculate the number of moles in each sample and compare them. 5 g of helium contains the greatest number of atoms.
Step-by-step explanation:
To determine which sample contains the greatest number of atoms, we need to calculate the number of moles in each sample. We can use the formula:
moles = mass / molar mass
Using the molar masses for lead, helium, uranium, and potassium, we can calculate the number of moles in each sample. By comparing the number of moles, we can determine which sample contains the greatest number of atoms. The sample with the greatest number of moles will also contain the greatest number of atoms.
Calculating the number of moles for each sample:
(a) 1 g of lead: moles = 1 g / 207.2 g/mol = 0.0048 moles
(b) 5 g of helium: moles = 5 g / 4.0026 g/mol = 1.2499 moles
(c) 10 g of uranium: moles = 10 g / 238.03 g/mol = 0.0420 moles
(d) 15 g of potassium: moles = 15 g / 39.0983 g/mol = 0.3835 moles
Based on these calculations, 5 g of helium contains the greatest number of atoms.