Why is the total mass always conserved in a chemical reaction? be sure that your explanation includes the discussion of atoms and bonds.

The total mass is always conserved in a chemical reaction because mass cannot be destroyed nor created. This is expressed in the law of conservation of mass. Atoms in a reaction cannot form another type of  atoms which has different properties than the original element. It can only exchange electrons which is responsible for bonding.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -