Understanding Elements, Compounds, and Chemical Reactions

What is the smallest part of an element that can exist?

• Compound

• Electron

• Atom

• Molecule

Which of the following is true about elements?

• They are made of different types of atoms.

• They can be found in the periodic table.

• They are always in the form of molecules.

• They are chemically combined in fixed proportions.

What is a compound?

• A substance made of one type of atom.

• A mixture of different molecules.

• A single element in molecular form.

• A substance with two or more elements chemically combined.

How is water represented in a chemical formula?

• H2

• HO2

• O2

• H2O

What must be done to a simple chemical equation?

• It must be balanced.

• It must include all elements in the periodic table.

• It must be written in molecular form.

• It must be written in words.