1. The smallest particle of an element which can take part in chemical reactions and may or may not exist independently is the   compound   neutron   nucleus   atom   Hint Half-n-half Clue   2. Atoms of an element with the same number of protons but different number of neutrons in the nucleus are known as   Isosters   Twin Atoms   Isotopes   Isobars   Half-n-half Clue   3. The three fundamental particles of the atom are   Mesons, Quarks and Anti-neutrino   Positron, Neutrino and Gamma Rays   Nucleus, Anti-quarks and Electrons   Proton, Neutron and Electron   Half-n-half Clue   4. Neutrons are   positively-charged particles with negligible mass.   positively-charged particles with mass.   neutral particles with mass.   negatively-charged particles with negligible mass.   Half-n-half Clue   5. The sum of the numbers of the protons and neutrons in the atom of an element is known as   Molecular Weight   Mass Number   Isotope Number   Atomic Number   Half-n-half Clue   6. The particle discovered as a result of cathode ray experiments is the   proton   electron   neutron   nucleus   Half-n-half Clue   7. The charge on the electron was discovered by   Mullikan   J. J. Thomson   Fermi   Faraday   Half-n-half Clue