Dinosaurs, cavemen, sabertooth tiger
Answer:
Helium is in the __1__ period. All elements in this period have __8__ shells around the nucleus. Also giving brainiest :)
Answer:
C
Explanation:
because it is product over reactants. hope this helps :)
Thomson concluded that electrons must be parts of the atoms of all elements. Millikan determined the charge and mass of the electron. What experimental evidence led Rutherford to conclude that an atom is mostly empty space? The majority of the alpha particles passed straight through the gold foil.