kk Atoms and Molecules Mastery

What is the smallest unit of an element?

• molecule

• compound

• atom

• ion

Which of the following particles is negatively charged?

• Alpha particle

• Neutron

• Electron

• Proton

What is the molecular formula for water?

• H2O2

• HO

• H3O

• H2O

Which of the following represents a compound?

• Carbon Dioxide (CO2)

• Oxygen (O2)

• Water (H2O)

• Nitrogen (N2)

What is the charge of a proton?

• -1 elementary charge

• +2 elementary charge

• 0 elementary charge

• +1 elementary charge

How many electrons are in a neutral atom of carbon?

• 6

• 10

• 8

• 4

What is the atomic number of oxygen?

• 12

• 10

• 6

• 8

Which of the following is a diatomic molecule?

• N2O

• CO2

• O2

• H2O

What is the mass number of an atom?

• The mass number is the number of electrons in an atom.

• The mass number is the total number of atoms in a molecule.

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

• The mass number is the average weight of an atom.

Which subatomic particle has no charge?

• neutron

• positron

• proton

• electron