Structure of an atom

What is the atomic number?

• number of protons
• number of neutrons

What number indicates the nucleus?

• 1
• 2
• 3
• 4

Oxygen’s atomic number is 8. This means that an oxygen atom must have

• 8 electrons
• 8 protons
• 8 neutrons
• a mass number of 8

What number indicates an electron?

• 1
• 2
• 3
• 4

Which statement best describes an electron?

• Smaller mass than a proton and a negative charge
• Smaller mass than a proton and a positive charge
• Greater mass than a proton and a negative charge
• Greater mass than a proton and a positive charge

What number indicates the nucleus?

• 1
• 2
• 3
• 4

What is at the center of every atom?

• An electron
• A compound
• A molecule
• A nucleus

Which two particles make up the nucleus of an atom?

• Protons and Electrons
• Protons and Neutrons
• Molecules and Compounds
• Neutrons and Electrons

What is the role of an electron in an atom?

• Electrons live inside the nucleus and carry a neutral charge.
• Electrons circle the nucleus and have a positive charge.
• Electrons circle the nucleus and have a negative charge.
• Electrons live inside the nucleus and have a negative charge.

In an atom, what is the number of protons equal to?

• The number of electrons.
• The number of neutrons.
• The number of molecules.
• The number of nuclei.