The mass of one s

Mass of one steel screw = 4.11 g

Mass of Earth = 5.98 × 10²⁴ kg = 5.98 × 10²⁷ g

We know, 1 mole = 6.022 x 10²³

One mole of screws weigh = 4.11 x 6.022 x 10²³ = 2.48 ×10²⁴ g

Mass of the Earth/ Mass of 1 mole of screws = 5.98 ×10²⁷ g / 2.48 ×10²⁴ g = 2.4 x 10³

Therefore, we can say that the mass of the earth is 2.4×10³ times the mass of screws.

The earth is 2400 times heavier than one mole of the screw.

OR

A pair of isotopes from the above particles is A and D. This is so because both the isotopes have the same number of protons, but they have a different number of neutrons.