Democritus named the smallest particles of matter _____ because they could not be divided.

True or False? John Dalton gathered evidence for the existence of atoms by measuring the masses of elements that reacted to form compounds.

Objects with like charges _____ each other.f

In Thomson's experiment, he concluded that the particles in the glowing beam had a(n) _____ charge because they were attracted to a positive plate.

Which of these did Rutherford conclude from the gold foil experiment?

The subatomic particle with a positive charge is the _____.

Which of these is NOT a property that varies among subatomic particles?

True or False: Two atoms of the same element can have different numbers of protons.

True or False: Two different elements can have the same atomic number.

Every atom of a given element does NOT have the same number of _____.

All oxygen atoms have 8 protons. How many neutrons does an atom of oxygen-18 have?

How is Bohr's model of the atom different from Rutherford's model?

True or False: When electrons release energy, some of the energy may be released as visible light.

True or False: Bohr's model was correct in assigning energy levels to electrons.

True or False: Scientists use the electron cloud model to describe the exact location of electrons around the nucleus.

True or False: An excited state is more stable than a ground state.