Unit 4 Chemical Bonding

Chemical Change

When one chemical substance is transformed into one or more different substances

Chemical Equation

Chemical formulas and symbols written to represent a reaction

Chemical Reaction

A process in which one or more substances, also called reactants, change to produce one or more different substances

Coefficient

A number placed in front of a chemical symbol or formula that represents the number of molecules

Covalent Bond

The results from the sharing of an electron pair between two nonmetals

Ionic Bond

Chemical bond formed when a metal gives up one or more valence electrons to a nonmetal

Endothermic

Chemical reaction in which heat is absorbed. It feels cold

Exothermic

Chemical reaction in which heat is released. It feels hot

Law of Conservation of Matter

Matter can’t be created or destroyed. Mass of all reactants must equal the mass of all products

Physical Change

A change in matter does not alter the chemical properties of the matter

Examples of Physical Change

Shape, size, changes of state, cutting, bending, dissolving, freezing, boiling, and melting

Chemical Change Indicators

Bubbles, new color, new odor, light, hot/cold