Calculate the mass, in grams, of each sample. d. 7.9×10²¹ uranium atoms

Key Concepts

Avogadro's Number

Avogadro's number, approximately 6.022 x 10^23, is the number of atoms, molecules, or particles in one mole of a substance. This constant allows chemists to convert between the number of particles and the amount of substance in moles, which is essential for stoichiometric calculations.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For uranium, the molar mass is approximately 238.03 g/mol. Knowing the molar mass is crucial for converting moles to grams, enabling the calculation of the mass of a given number of atoms.

Mass Calculation from Atoms

To calculate the mass of a sample from the number of atoms, one first converts the number of atoms to moles using Avogadro's number. Then, the number of moles is multiplied by the molar mass of the element to find the mass in grams. This process is fundamental in quantitative chemistry for determining the mass of elements in a sample.