Final answer:
A 14 g sample of lithium will contain approximately 1.22 x 10^24 molecules, which is more than the 3.0 x 10^23 molecules asked about. Therefore, less than 14 g of lithium would have 3.0 x 10^23 molecules.
Step-by-step explanation:
To determine which sample contains a total of 3.0 x 10^23 molecules of lithium (Li), we need to understand the concept of Avogadro's number and molar mass. Avogadro's number (6.02 x 10^23) is the number of atoms, ions, or molecules in one mole of a substance. The molar mass of lithium is approximately 6.94 g/mol. Using these values, we can calculate the number of moles in a 14 g sample of lithium by dividing the sample mass by the molar mass of Li.
Number of moles in 14 g of Li = 14 g ÷ 6.94 g/mol = 2.02 mol
Since 1 mole of any substance contains Avogadro's number of molecules, we can multiply the number of moles of lithium by Avogadro's number to determine the number of molecules:
Molecules in 14 g of Li = 2.02 mol x 6.02 x 10^23 molecules/mol
When calculating, we find that there would be approximately 1.22 x 10^24 molecules in 14 g of Li, which is more than the 3.0 x 10^23 molecules being queried. Therefore, a smaller mass of lithium than 14 g would contain 3.0 x 10^23 molecules.