1. The nucleus of an atom has almost the entire weight of the atom and it consists of protons and neutrons.   True   False   2. The atom is mainly empty.   True   False   3. Atomic weight of an element is the mass of an atom of that element in grams.   True   False   4. Atoms are electrically neutral.   True   False   5. In a neutral atom, the number of electrons and protons is equal.   True   False   6. Since an atom of the element sodium contains 11 protons and 12 neutrons, its atomic number is 23.   True   False   7. An element is a substance made up of different kinds of atoms.   True   False