Chemistry Unit Test Review

Which subatomic particle has a mass of almost zero (0.00055) amu, a negative charge, and is located outside of the nucleus?

Answer explanation

Electrons have a mass of 0.00055 amu, have a negative charge, and are located in the electron cloud.

Which subatomic particle has a mass of 1 amu, a neutral charge, and is located inside the nucleus?

Answer explanation

Neutrons have an atomic mass of 1 amu, have a neutral charge, and are located in the nucleus of an atom. Neutrons and protons equal the atomic mass of an atom.

Which subatomic particle has a mass of 1 amu, a positive charge, and is located inside the nucleus?

Answer explanation

Protons have an atomic mass of 1 amu, have a positive charge, and are located in the nucleus of an atom. The protons and neutrons equal the atomic mass of an atom.

Identify the subatomic particles A, B, and C using the data table provided in the picture.

• A-proton

  B-neutron

  C-electron

• A-electron

  B-proton

  C-neutron

• A-neutron

  B-proton

  C-electron

Briefly describe the structure of an atom. Be sure to include the terms nucleus, electron cloud, protons, neutrons, and electrons in your description.

What characteristic is the most important information to know when trying to determine a element's identity?

• Atomic Number=Protons

• Atomic Mass=Protons+Neutrons

• Atomic Number=Neutrons

Identify the element using the Bohr model in the picture.

• Oxygen

• Fluorine

• Nitrogen

• Neon

Identify mystery elements A, B, and C using the data table.

• A. Oxygen

  B. Calcium

  C. Aluminum

• A. Phosphorus

  B. Calcium

  C. Silicon

• A. Oxygen

  B. Yttrium

  C. Iron

• A. Oxygen

  B. Potassium

  C. Aluminum

What characteristic determines an element's chemical properties such as reactivity?

• Electrons

• Protons

• Valence Electrons

• Neutrons

Which element shown below would be the least reactive?

• Sodium

• Neon

• Chlorine

Answer explanation

Remember valence electrons are happy when they reach 2, 8, or 8 electrons on the outer shell of an atom.