Louis+DeBroglie

2. What is true of most of the space inside an atom? //The nucleus contains most of the mass of an atom. It occupies little space.// 4. Explain the difference between atomic number and atomic mass. //Atomic mass is the total weight of an atom. Atomic number is equal to the number of protons in one atom.// 6. What is an isotope? //One of two atoms with the same atomic number, but has a different amout of neutrons.//