How many atoms are there in 90.2 grams of selenium?

First calculate the moles of selenium by multiplying the mass x molar mass 90.2 × 78.96 = 7122.2 moles
Number of moles multiplied by avogadros number gives number of atoms 7122.2 × 6.022 × 10^{23} = 4.289×10^{27} atoms

Answered by Sabrina211 | 2024-06-10

To find the number of atoms in 90.2 grams of selenium, calculate the number of moles using its molar mass of 78.96 g/mol, which gives approximately 1.143 moles. Then, multiply by Avogadro's number (6.022 x 10^23) to find that there are about 6.88 x 10^23 atoms of selenium in that mass.
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Answered by Sabrina211 | 2024-12-24