Summer School Biology - CH 2 - Section II and III Quiz

What are the three particles that make up an atome?

• Protons, Neutrons, and Isotopes

• Neutrons, Isotopes, and Electrons

• Positives, Negatives, and Electrons

• Protons, Neutrons, and Electrons

What is the smallest particle of an element that has the elements's properties?

• Compound

• Molecule

• Atom

• Nucleus

Isotopes are atoms of the same element with the same number of protons and what?

• a different number of electrons

• a different number of nuetrons

• a different number of molecules

• the same number of neutrons

What are molecules?

• units formed by ionic bonds

• compounds

• units formed by covalent bonds

• pairs of negative ions

During a chemical reaction, substances become new substances by the ________.

• appearance of new isotopes

• elimination of isotopes

• breaking apart of atoms

• breaking or forming of chemical bonds

When sodium and chlorine react, they form

• an ionic bond

• a gas

• a covalent bond

• a polar molecule

What is a covalent bond?

• bond in which atoms share electrons

• bond in which electrons are lost by one element and gained by another

• hydrogen bond

• unstable bond between water molcules

An atom that has an unstable nucleus is?

• Radioactive

• Not Radioactive

• a Molecule

• an Ion

Two elements linked chemically in definite proportions are called what?

• molecules

• a compound

• isotopes

• a complex substance

What do enzymes do in an organism?

• Store energy

• Speed up chemical reactions

• Slow down chemical reactions

• Nothing, they are junk DNA