Which of the following is true about an atom of iron and an atom of copper? They have different masses.
Both have the same properties.
They have an equal number of protons.
Both have different types of sub-atomic particles.

They have different mass and Both have different types of sub-atomic partials

Explanation:

specific gravity is the density of a substance divided by the density of water. since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density

so "c" is the answer

plz give brainliest