Atom

The _ is a small, dense region at the center of the atom. It consists of positive protons and neutral neutrons, so it has an overall positive charge.

• protons

• neutrons

• nucleus

• electrons

The building blocks of all matter is:

• cells

• atoms

• elements

• mass

What is the smallest unit of a chemical element that retains its chemical properties?

• Molecule

• Atom

• Compound

• Mixture

Which part of the atom contains the electrons?

• Nucleus

• Proton

• Electron cloud

• Neutron

Who is credited with the discovery of the electron?

• Albert Einstein

• Niels Bohr

• J.J. Thomson

• Ernest Rutherford

What is the charge of a neutron?

• Positive

• Negative

• Neutral

• Variable

Which scientist proposed the planetary model of the atom?

• Niels Bohr

• J.J. Thomson

• Ernest Rutherford

• Dmitri Mendeleev

What is the term for the number of protons in the nucleus of an atom?

• Atomic mass

• Atomic number

• Isotope

• Valence

Which subatomic particle is responsible for chemical bonding?

• Proton

• Neutron

• Electron

• Photon

What is the term for atoms of the same element with different numbers of neutrons?

• Isotopes

• Ions

• Molecules

• Compounds