Biology - Ch. 2 Sections 3-4

Proton

subatomic particle with a single positive electrical charge, found in the nucleus of an atom

Anion

Negatively charged ion

salt

A compound resulting from the formation of an ionic bond; also called an ionic compound

orbital

three dimensional space where an electron is found 90% of the time

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions

Valence electron

an electron in the outermost electron shell

Chemical reaction

Making and breaking of chemical bonds, leading to changes in the composition of matter

Valence

Bonding capacity of given atom; equals number of electrons required to complete outermost shell

Van der Waals interactions

weak attractions between molecules or parts of molecules that result from transient local partial charges.

polar covalent bond

a covalent bond between atoms that differ in electronegativity. the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive

double bond

sharing of two pairs of valence electrons by two atoms

compound

a substance consisting of two or more different elements combined in a fixed ratio

electronegativity

attraction of particular atom for electrons of a covalent bond

cation

postivite charged ion

ionic compound

compounds formed by ionic bonds

nonpolar covalent bond

2 atoms of the same element, the electons are shared equally resulting in the same electroneagtivity

single bond

sharing of a pair of valence electrons by two atoms

chemical equilibrium

point where reactions offset each other exactly

hydrogen bond

when bounded to an electroneagtive atom, hydrogen atom has partial +, resulting in being attracted to a partial -

molecule

2+ atoms held together by covalent bonds