Final answer:
The mass of 75,000 oxygen molecules, given the mass of one oxygen molecule, is 5.3 x 10^-23 grams, is 3.975 x 10^-18 grams when calculated and expressed in scientific notation.
Step-by-step explanation:
To calculate the mass of 75,000 oxygen molecules expressed in scientific notation, when given that 1 oxygen molecule has a mass of 5.3 x 10-23 grams, you would perform the following calculation:
Mass of 1 oxygen molecule = 5.3 x 10-23 grams
Mass of 75,000 oxygen molecules = 75,000 x 5.3 x 10-23
This can be written as:
Mass of 75,000 oxygen molecules = (7.5 x 104) x (5.3 x 10-23)
By multiplying these two numbers in scientific notation, you get:
Mass of 75,000 oxygen molecules = 7.5 x 5.3 x 10(4-23)
Mass of 75,000 oxygen molecules = 39.75 x 10-19 grams
To express 39.75 x 10-19 grams in scientific notation correctly, it should be:
Mass of 75,000 oxygen molecules = 3.975 x 10-18 grams