Unit 4: Atomic Structure

The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

• Element

• Atom

• Electron

• Molecule

Which subatomic particle has a negative charge?

• Electron

• Alpha Particle

• Neutron

• Proton

Which subatomic particle has a positive charge?

• Electron

• Alpha Particle

• Neutron

• Proton

Which subatomic particle has a neutral charge?

• Electron

• Alpha Particle

• Neutron

• Proton

What makes up an atom's nucleus?

• Protons

• Neutrons

• Electrons

Which property of an atom identifies which element it is?

• number of electrons

• number of protons

• number of neutrons

• number of protons plus neutrons

To find the number of neutrons in an atom, you would subtract:

• proton number from electron number

• atomic number from mass number

• atomic number from electron number

• isotope number from atomic number

Which statement is true about oxygen-17 and oxygen-18?

• They don't have the same number of protons

• Their atoms have an identical mass

• They are isotopes of oxygen

• They have the same mass number

In Niels Bohr's model of the atom, electrons move

• like balls rolling down a hill

• like planets orbiting the sun

• like popcorn in a popcorn popper

• like beach balls on water waves

The sum of the number of protons and neutrons in the nucleus is the

• atomic number

• mass number

• electron number

• energy level