To determine the number of atoms present in a given mass of a substance, you need to use the concept of moles and Avogadro's number.
First, you need to calculate the number of moles of nitrogen in 28 g. The molar mass of nitrogen (N₂) is approximately 28 g/mol. Therefore, the number of moles can be calculated as:
Number of moles = Mass / Molar mass Number of moles = 28 g / 28 g/mol Number of moles = 1 mol
Since 1 mole of any substance contains Avogadro's number (6.022 x 10^23) of particles (atoms, molecules, ions, etc.), in this case, it refers to the number of nitrogen atoms.
Therefore, 28 g of nitrogen contains approximately 6.022 x 10^23 nitrogen atoms.