1.5 Atomic Structure & Electron Configuration

J.J. Thomson's model of the atom can be summarized with the visual image of:

• none of the above
• a small central nucleus and an electron cloud
• planets orbiting the sun
• bees around a hive
• plum pudding

The apparatus pictured here helped to determine:

• that mass and energy are related by E=mc2
• that electrons have mass
• that energy travels at the speed of light
• that atoms are mostly empty space
• the existence of electrons

If the Thomson model of the atom had been correct, Rutherford would have observed

• alpha particles going through the foil with little or no deflection.
• alpha particles greatly deflected by the metal foil.
• alpha particles bouncing off the foil.
• positive particles formed in the foil.
• None of the above observations is consistent with the Thomson model of the atom.

Rutherford's experiment was important because it showed that:

• radioactive elements gave off alpha particles.
• gold foil can be made to be only a few atoms thick.
• a zinc sulfide screen scintillates when struck by a charged particle.
• the mass of the atom is uniformly distributed throughout the atom.
• an atom is mostly empty space.

Which of the following statements is/are true?

• O-18 and F-19 have the same number of neutrons.
• C-14 and N-14 are isotopes of each other because their mass numbers are the same.
• has the same number of electrons as Ne.
• a and b
• a and c

The statement in Dalton's atomic theory that all atoms of the same element are exactly alike has been replaced in the modern atomic theory because of the discovery of:

• atoms of the same element with different masses
• the bending of cathode rays by magnets
• electrons and protons in an atom
• the law of multiple proportions

Which one of the following statements about the modern value of atomic structure is false?

• the electrons occupy a very large volume compared to the nucleus.
• Almost all of the mass of the atom is concentrated in the nucleus.
• The protons and neutrons in the nucleus are very tightly packed.
• The number of protons and neutrons is always the same in the neutral atom.

Which of the following conclusions can be drawn from J. J. Thomson's cathode ray experiments?

• Atoms contain electrons.
• Practically all the mass of an atom is contained in its nucleus.
• Atoms contain protons, neutrons, and electrons.
• Atoms have a positively charged nucleus surrounded by an electron cloud.
• No two electrons in one atom can have the same four quantum numbers.

An impossible ground state electronic configurations (pick multiple)

• 1s2 2s2 2p5 3s2 3p5
• 1s2 2s2 2p6 3s2 3p6
• 1s2 2s2 2p6 2d10 3s2 3p6
• 1s2 2s2 2p6 3s2 3p6 3d5
• 1s2 2s2 2p6 3s2 3p6 3d3 4s2

The ground-state configurations for the atoms of a transition element (pick multiple)

• 1s2 2s2 2p5 3s2 3p5
• 1s2 2s2 2p6 3s2 3p6
• 1s2 2s2 2p6 2d10 3s2 3p6
• 1s2 2s2 2p6 3s2 3p6 3d5
• 1s2 2s2 2p6 3s2 3p6 3d3 4s2