Convert the mass to moles .
85.1 g ÷ 20.18 g/mol = 4.21704658
convert the moles to molecules
4.2170 mol × 6.022^23 molecules/mol = 2.539^24
Answer:

Explanation:
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In this case, it is possible to treat this problem by using a proportional factor which indicates one iron nail equals 2.0 grams:

Now, for an amount of 6.022x10²³ nails, the corresponding mass will be:

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The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus.
Answer:
compound light microscope