Atoms and Molecules

Which of the following best describes an atom?

• Protons and electrons grouped together in a random pattern

• Protons and electrons grouped together in an alternating pattern

• A core of protons and neutrons surrounded by electrons

• A core of electrons and neutrons surrounded by protons

Which subatomic particle is farthest from the center of an atom?

• Electron

• Neutron

• Nucleus

• Proton

Which of the following particles can be found in the nucleus of an atom?

• Protons only

• Electrons only

• Protons and electrons

• Protons and neutrons

In the diagram, the letter "b" is pointing to which subatomic particle?

• Electron

• Proton

• Neutron

• Nucleus

Which of the following particles are NOT located in the nucleus of an atom?

• Protons only

• Electrons only

• Protons and electrons

• Protons and neutrons

Which statement best describes the part of the atom that is shown by the

arrow?

• It is an electron and it has a negative charge.

• It is an electron and it has a positive charge.

• It is an proton and it has a negative charge.

• It is an electron and it has a positive charge.

The subatomic particles located in the electron cloud have a _______ charge

• Positive

• Negative

• Neutral

• Positive and negative

Which best describes the relationship between the subatomic particles in any neutral atom?

• The number of protons equals the number of electrons

• The number of protons equals the number of neutrons

• The number of neutrons equals the number of electrons

• The number of neutrons is greater than the number of protons

Answer explanation

A neutral atom is an atom with the same number of electrons(negative) as protons(positive). It’s called “neutral” because, together, the charges equal 0.

Which diagram correctly illustrates the structure of an atom?

• Model A

• Model B

• Model C

• None are correct

How many electrons are in an electrically neutral atom of potassium?

• 19

• 20

• 39.10

• 68.10