High School Chemistry Vocabulary

A substance with a pH lower than 7 that can dissolve certain materials and often has a sour taste

Lemon juice is an acid, which is why it tastes sour.

The smallest unit of a chemical element that still has the properties of that element

Every substance around us is made up of tiny atoms.

A substance with a pH higher than 7 that can neutralize an acid and often feels slippery

Baking soda is a base that can be used to cancel out the effects of an acid.

The force that holds two or more atoms together in a molecule or compound

The chemical bond between hydrogen and oxygen atoms creates a water molecule.

A substance that speeds up a chemical reaction without being used up or changed itself

Enzymes in your body act as a catalyst to help break down food quickly.

A substance formed when two or more different elements are chemically joined together

Water is a compound because it contains hydrogen and oxygen atoms bonded together.

A very small particle with a negative electrical charge that moves around the nucleus of an atom

Electricity is the flow of electrons through a conductor like copper wire.

A pure substance made of only one type of atom that cannot be broken down into simpler substances

Gold and oxygen are both examples of a chemical element.

An atom or group of atoms that has gained or lost electrons, giving it a positive or negative electrical charge

When salt dissolves in water, it breaks into positive and negative ions.

A form of a chemical element that has the same number of protons but a different number of neutrons in its nucleus

Carbon-14 is a radioactive isotope of carbon used to date ancient objects.

A unit used in chemistry to measure a very large number of atoms or molecules, equal to about 6.022 times 10 to the power of 23

The teacher asked the students to calculate how many grams are in one mole of water.

The smallest unit of a substance, made of two or more atoms joined together

A water molecule is made of two hydrogen atoms and one oxygen atom.

A particle found in the nucleus of an atom that has no electrical charge

Adding a neutron to an atom creates a different isotope of the same element.

A chemical process in which a substance loses electrons, often when it combines with oxygen

The rusting of iron is an example of oxidation caused by exposure to air and water.

A new substance that is formed as a result of a chemical reaction

Water is the main product when hydrogen gas burns in oxygen.

A particle found in the nucleus of an atom that has a positive electrical charge

The number of protons in an atom determines which element it is.

A substance that is present at the start of a chemical reaction and is changed during the reaction

In the reaction to make water, hydrogen and oxygen are the reactants.

A substance that is dissolved in a liquid to make a solution

In saltwater, salt is the solute because it dissolves in the water.

A liquid that dissolves another substance to form a solution

Water is often called the universal solvent because it can dissolve many substances.

The ability of an atom to combine with other atoms, determined by the number of electrons in its outer shell

Carbon has a valence of four, which means it can form bonds with four other atoms.