Atomic Theory Review

Which conclusion was a direct result of the gold foil experiment?

• An atom is mostly empty space with a dense, positively charged nucleus.

• An electron has properties of both waves and particles.

• An atom is composed of at least three types of subatomic particles.

• An electron has a positive charge and is located inside the nucleus.

The major portion of an atom’s mass is made up of:

• Electrons and protons

• Neutrons and protons

• Neutrons and positrons

• Electrons and neutrons

Which subatomic particle has no charge?

• Alpha particle

• Electron

• Beta particle

• Neutron

What is the structure of a krypton-85 atom?

• 36 electrons, 36 protons, and 49 neutrons

• 49 electrons, 49 protons, and 85 neutrons

• 36 electrons, 36 protons, and 84 neutrons

• 49 electrons, 49 protons, and 49 neutrons

Which statement about an atom identifies the element?

• The sum of the number of protons and neutrons in the atom is 3.

• The difference between the number of neutrons and protons in the atom is 1.

• The atom has 1 proton.

• The atom has 2 neutrons.

Which statement describes the distribution of charge in an atom?

• A neutral nucleus is surrounded by one or more positively charged electrons.

• A positively charged nucleus is surrounded by one or more negatively charged electrons.

• A neutral nucleus is surrounded by one or more negatively charged electrons.

• A positively charged nucleus is surrounded by one or more positively charged electrons.

The weighted average of the atomic masses of the naturally occurring isotopes of an element is called the:

• Formula mass of each isotope

• Mass number of each isotope

• Atomic number of the element

• Atomic mass of the element

Which two particles each have a mass approximately equal to one atomic mass unit?

• Electron and positron

• Electron and neutron

• Proton and electron

• Proton and neutron

How many valence electrons are present in krypton?

• 4

• 16

• 36

• 8

What term is used for electrons in the outermost shell or energy level?

• Core electrons

• Orbital electrons

• Inner electrons

• Valence electrons