Term | Definition |
symbol(s) | One or two letters used to represent an element chemical |
formula | A combination of symbols and numbers that represent the number and types of elements (atoms) present in a compound |
subscript | A small number to the right of a symbol that is written below the normal line of letters to show how many atoms of an element are present in a substance. No subscript means there is only one atom present. |
chemical reaction | When substances interact to form one or more new substances with different properties than the original substances |
chemical equation | A combination of chemical formulas used to describe what happens in a chemical reaction. The equation identifies the reactants and resulting products. |
Coefficient | A number written in front of a chemical formula to show how many molecules of that substance are present |
Reactant | Formulas written on the left side of the arrow symbol (→ ) are the starting substances in a chemical reaction. |
Product | Formulas written on the right side of the arrow symbol (→ ) are the new substances formed in a chemical reaction. |
Yields | An arrow symbol that shows a reaction has taken place. The reactants have reacted to produce a new substance (the product). |
Compound | A substance composed of two or more elements chemically combined and in a definite proportion |
physical change | A change in which the characteristics of a substance are only changed physically and the original properties stay the same |
chemical change | A change in which a substance (or substances) is changed into one or more new substances with different properties than the original substances |
law of conservation of mass | Matter is not created or destroyed, only changed. The number of atoms in the reactants must be equal to the number of atoms in the product. |
precipitate | A solid that forms as a result of a chemical reaction. It will fall to the bottom of the container. |