Chapter 4 test

First Name

Last Name

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

• element
• atom
• electron
• molecule

Which statement accurately represents the arrangement of electrons in Bohr’s atomic model?

• Electrons vibrate in fixed locations around the nucleus.
• Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.
• Electrons travel around the nucleus in fixed energy levels with equal amounts of energy.
• Electrons travel randomly in the relatively large space outside the nucleus.

Which model of the atom describes electrons as being in 'clouds' around the nucleus?

• Bohr model
• Electron cloud model
• Rutherford model
• Dalton Model

In Niels Bohr’s model of the atom, electrons move

• like balls rolling down a hill.
• like planets orbiting the sun.
• like popcorn in a popcorn popper.
• like beach balls on water waves.

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

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

Choose the 3 subatomic particles. This is an all-or-no-points question.

• protons
• neutrons
• quarks
• ions
• electrons

What is an alpha particle?

• Fast moving positively charges particle emitted from Uranium
• a nucleus of unranium
• an electron of an uranium atom
• the first particle of an atom.

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