Unit 2 Atoms and the Periodic Table Review

What is an Atom?

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

• element
• atom
• electron
• molecule

Using your Periodic Table, what is the atomic number for Oxygen?

Using your Periodic Table, how many neutrons does Chlorine have?

Using your Period Table, how many electrons does Argon have?

Democritus thought that matter was made of tiny particles

• of earth, air, fire, and water.
• that could not be divided.
• that could be divided.
• that were all round and smooth.

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

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, the 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