15 terms

7th Grade Science: Chemical Reaction Basics

Vocabulary list for the 7th grade chemical experimental design module
Evidence of a Chemical Reaction
these observations may indicate a chemical reaction has occurred: color change, energy (temperature) change, a gas is produced (bubbling), a precipitate (solid) forms, or light is released.
chemical reaction
A process in which bonds between atoms are broken and new bonds are formed producing substances which are different from the starting materials.
the substances that you start with in a chemical reaction
the new substances that are formed in a chemical reaction
a pure substance that contains atoms of two or more different kinds of elements combined in a fixed ratio.
physical change
A process in which some properties of a substance change, but atoms are NOT rearranged and no new substances are formed.
chemical change
A process in which atoms are rearranged and that produces one or more new substances with different chemical and physical properties.
chemical bond
An attractive force that holds together the atoms in a molecule.
chemical formula
a shorthand way using letters and numbers to show which elements are in a compound
chemical equation
writing symbols to represent the reactants and products in a chemical reaction
a substance used to show the presences of something or that a reaction has happened
a substance that speeds up a chemical reaction
regular sized numbers in front of molecules or atoms that tell how many copies there are in an equation
small numbers written after and to the lower right of certain atoms that tell how many atoms are in the formula for that molecule
a solid that forms as a result of mixing two solutions