1. An atom consists of a central nucleus containing positively-charged protons and negatively-charged neutrons.   True   False   2. Since an atom of the element sodium contains 11 protons and 12 neutrons, its atomic number is 23.   True   False   3. Electrons are present in the nucleus.   True   False   4. Atomic number of an element is the number of neutrons present in the nucleus of the atom.   True   False   5. Electrons revolve around the nucleus in shells or orbits.   True   False   6. The nucleus consists of protons and neutrons and is negatively-charged.   True   False   7. Atomic weight of an element is the mass of an atom of that element in grams.   True   False