Answer:
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. ... Elements contain only one type of atom.
Explanation:
Changes into new substances called product.
Answer:
the mass number
Explanation:
Isotopes are numerous forms of one single element. In simple terms, atomic weights are different for the isotopes. Isotopes refer to the atoms that have the same number of protons but different neutron numbers. The physical properties of the isotopes vary because these properties also based on mass. These variations can be used to distinguish isotopes of an element from each other by applying methods such as fractional distillation and diffusion.