Chapter 4 test

The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

• element
• atom
• electron
• molecule

Which of the following most accurately represents John Dalton’s model of the atom?

• a tiny, solid sphere with an unpredictable mass for a given element
• a hollow sphere with a dense nucleus
• a tiny, solid sphere with a predictable mass for a given element
• a sphere that is hollow throughout

J. J. Thomson’s experiments provided evidence that an atom

• is the smallest particle of matter.
• contains negatively charged particles.
• has a negative charge.
• has a positive charge.

Rutherford’s gold foil experiment provided evidence for which of the following statements?

• Negative and positive charges are spread evenly throughout an atom.
• Alpha particles have a positive charge.
• Gold is not as dense as previously thought.
• There is a dense, positively charged mass in the center of an atom.

Who provided evidence for the existence of a nucleus in an atom

• John Dalton
• J. J. Thomson
• Democritus
• Ernest Rutherford

In an atomic model that includes a nucleus, positive charge is

• concentrated in the center of an atom.
• spread evenly throughout an atom.
• concentrated at multiple sites in an atom.
• located in the space outside the nucleus.

Which subatomic particle has a negative charge?

• electron
• alpha particle
• neutron
• proton

Which statement about subatomic particles is NOT true?

• Protons and neutrons have almost the same mass.
• Protons and electrons have opposite charges.
• Unlike protons and electrons, neutrons have no charge.
• Protons and neutrons have the same charge.

Which statement about subatomic particles is true?

• Protons, neutrons, and electrons all have about the same mass.
• Unlike protons or neutrons, electrons have no mass.
• Neutrons have no charge and no mass.
• An electron has far less mass than either a proton or neutron.

Which of the following is unique for any given element?

• the number of neutrons
• the charge on the electrons
• the number of protons
• the mass of a neutron