1. Since an atom of the element sodium contains 11 protons and 12 neutrons, its atomic number is 23.   True   False   2. Isotopes have same atomic weight.   True   False   3. Atomic weight of an element is the mass of an atom of that element in grams.   True   False   4. The elements are arranged in order of decreasing atomic numbers in a table called the periodic table.   True   False   5. An element is a substance made up of different kinds of atoms.   True   False   6. The nucleus of an atom has almost the entire weight of the atom and it consists of protons and neutrons.   True   False   7. The number of electrons in a neutral atom is equal to its atomic number.   True   False