1. Isotopes have same atomic weight.   True   False   2. Isotopes have same atomic number.   True   False   3. Since an atom of the element sodium contains 11 protons and 12 neutrons, its atomic number is 23.   True   False   4. Electrons are present in the nucleus.   True   False   5. In a neutral atom, the number of electrons and protons is equal.   True   False   6. Atomic weight of an element is the mass of an atom of that element in grams.   True   False   7. Atoms are electrically neutral.   True   False