The mass of a single oxygen atom, approximately 2.7×10^-23 grams, can be written in scientific notation as 2.7 × 10^-23 g.
To find the mass of 40,000 oxygen atoms, we can multiply the mass of a single oxygen atom by the number of atoms:
Mass of 40,000 oxygen atoms = (Mass of a single oxygen atom) × (Number of atoms) = (2.7 × 10^-23 g) × (40,000) = 1.08 × 10^-18 g
Therefore, the mass of 40,000 oxygen atoms is approximately 1.08 × 10^-18 grams.