Science 8 Unit 4 Vocabulary

Product

• A substance that is formed as the result of a chemical reaction.

• A type of chemical bond between atoms.

• A reactant that undergoes a transformation.

• A catalyst that speeds up a chemical reaction.

Exothermic

• A process or reaction that absorbs energy in the form of heat.

• A process or reaction that releases energy in the form of heat.

• A process that occurs at constant temperature.

• A reaction that requires a catalyst to proceed.

Conservation of Matter

• A principle stating that mass can be created in a closed system through chemical reactions.

• A principle stating that mass cannot be created or destroyed in a closed system through ordinary chemical reactions or physical transformations.

• A principle that allows for the transformation of energy into mass in a closed system.

• A principle that states that matter can be destroyed but not created.

Reactant

• A substance that takes part in and undergoes change during a reaction.

• A product formed after a chemical reaction.

• A catalyst that speeds up a reaction without being consumed.

• A byproduct that does not affect the main reaction.

Chemical Reaction

• A process that involves rearrangement of the molecular or ionic structure of a substance.

• A method of separating mixtures based on their physical properties.

• A technique used to measure the pH level of a solution.

• A reaction that occurs only in the presence of a catalyst.

Ion

• A neutral atom with no charge.

• An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

• A particle that is always positively charged.

• A molecule that cannot gain or lose electrons.

Chemical Equation

• A symbolic representation of a chemical reaction in the form of symbols and formulas.

• A numerical representation of a chemical reaction using numbers only.

• A graphical representation of a chemical reaction using diagrams.

• A verbal description of a chemical reaction using words.

Subscript

• A number written slightly below and to the right of a chemical symbol in a formula, representing the number of atoms of the element in the compound.

• A number written above a chemical symbol indicating the charge of the element.

• A notation used to represent the state of matter of a compound.

• A symbol used to denote the molecular weight of a compound.

Endothermic

• A process or reaction that absorbs energy in the form of heat.

• A process that releases energy in the form of heat.

• A reaction that occurs spontaneously without energy input.

• A process that involves the breaking of chemical bonds.

Coefficient

• A number placed in front of a chemical formula in an equation to balance the equation.

• A type of chemical bond between two atoms.

• The total number of atoms in a molecule.

• A measure of the concentration of a solution.