What differentiates the isotopes of an element?

An isotope will have the same number of protons and electrons as the element on the periodic table, but it will have a different number of neutrons, so the atomic mass will change. Different isotopes of the same element have different numbers of neutrons, so they all have different masses

4- c, because all matter stays the same no matter what. it is still there. 5- b, because matter is known as mass. 6-c because, flammability is a chemical property. malleability is changing the shape of an object.

The formula is (nh4)2co3