Which of the following for an object should be known to calculate its density? the heat present in it the amount of matter in it the force of gravity acting on it the space between the object and another object

The amount of matter

that would be the amount of matter in it!

Explanation: i got it right in my test

A is the correct answer. Molecules are groups of atoms that stay together because of chemical bonds. These can be covalent bonds, where electrons are shared between atoms, or ionic bonds, where the difference in (positive or negative) charge between ions causes them to attract.