bonds,pH,chemical equation :AP1-2 vocab

Covalent Bonds

Formed when 2 non-metal atoms share 1 or more pairs of valence electrons.

Valence Electrons

Electrons in the outer energy level or shell of an atom; these electrons are involved in bonding.

Ionic Bond

An attraction between positively and negatively charged ions in an ionic compound. Atoms give up or gain electrons and the 2 oppositely charged atoms attract.

Metallic Bonds

Forms when many metal atoms share their pooled valence electrons.

Alloy

A mixture of a metal with 1 or more other elements.

Reactants

The starting substances in a chemical reaction.

Products

The substances produced by the chemical reaction.

Coefficients

A number placed in front of an element symbol or chemical formula in an equation.

Subscript

The small, subset numbers next to chemical symbols in a molecule; shows the identity of the substance.

Endothermic Reaction

A chemical reaction that absorbs thermal energy.

Exothermic Reaction

A chemical reaction that releases thermal energy.

Activation Energy

The energy required to get a chemical reaction started.

Catalyst

A substance that increases the rate of a chemical reaction, but is not changed or used up in the reaction.