General Chemistry Midterm Review

What is the smallest unit of matter? It is composed of protons and neutrons, held together in the nucleus, and electrons around the nucleus in different electron orbitals, which form an electron cloud.

• cell

• nucleus

• atom

• electron

What is a subatomic particle with a positive charge that is in the nucleus of an atom?

• neutron

• proton

• electron

• valence electron

What is a subatomic particle without an electric charge, located in the nucleus of an atom?

• neutron

• proton

• electron

• valence electron

What is a subatomic particle with a negative charge? It is found in the electron cloud surrounding the nucleus.

• neutron

• proton

• electron

• electron cloud

What is the center of an atom containing protons and neutrons?

• nucleus

• neutron

• proton

• electron cloud

What is material that has mass and takes up space?

• volume

• mass

• matter

• density

Who was the first contributor to the atomic theory?

• John Dalton

• Ernest Rutherford

• JJ Thompson

• Democritus

• Neils Bohr

What were J. J. Thomson's three contributions to the atomic theory?

• Discovered the electron

• Discovered the nucleus -did the gold foil experiment

• Used the cathode ray tube in his discovery

• Created a model of the atom with electrons moving around the nucleus in fixed orbits

• Created the "plum pudding" model of the atom

What is Neils Bohr's contribution to the atomic theory?

• Created the atomic theory

• Created a model of the atom with electrons moving around the nucleus in a fixed orbits

• Discovered that the proton had a positive charge

• Believed that atoms of a given element are identical

• Discovered the electron

What were Ernest Rutherford's three contributions to atomic theory?

• Discovered that the atom is mostly empty space

• Discovered the nucleus- did the gold foil experiment

• Used the cathode ray tube in his discovery

• Discovered the electron

• Discovered that the proton had a positive charge