Midterm Review

The nucleus of an atom is:

• negatively charged and has a low density.

• negatively charged and has a high density.

• positively charged and has a low density.

• positively charged and has a high density.

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Thomson’s plum-pudding model describes an atom as:

• neutral material with negatively charged electrons scattered throughout.

• positively charged material with negatively charged electrons scattered throughout.

• negatively charged material with negatively charged electrons spaced evenly throughout.

• positively charged material with neutral electrons throughout.

Thomson performed an experiment where he discovered that cathode rays are deflected by a magnet and attracted by a positively charged plate. What did this prove about the particles that make up the rays?

• They have a greater mass.

• They are neutral.

• Likes attract likes.

• They are negatively charged.

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Which BEST completes this sentence? Bohr proposed that an electron is found only in _______ around the nucleus of an atom.

• the charged areas

• the magnetic field

• circular patterns

• random areas

The quantum mechanical model of the atom:

• is concerned with the probability of finding an electron in a certain position.

• was proposed by Niels Bohr.

• defines the exact path of an electron around the nucleus.

• has many analogies in the visible world.

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The number of neutrons in the nucleus of an atom can be calculated by

• adding together the number of electrons and protons.

• subtracting the number of protons from the number of electrons.

• subtracting the number of protons from the mass number.

• adding the mass number to the number of protons.

The number of protons in the nucleus of an atom of a specific element is the same as that element’s

• atomic mass.

• energy levels.

• atomic number.

• neutrons.

Which element is paired with the correct symbol?

• Neon, N

• Gold, Go

• Iron, I

• Boron, B

All of the following are physical properties of water EXCEPT

• boiling point of 100°C

• colorless liquid

• able to dissolve table salt

• separates into hydrogen and oxygen

According to Hund’s rule, the first three electrons that enter into p orbitals must have

• parallel spins.

• opposite spins.

• low energy levels.

• opposite charges.