chemistry

Unit 4 periodic table vocab

Ionic Bonding

Involves a transfer of electrons, one element loses electrons and the other gains electrons.

Covalent Bonding

involves a sharing of electrons. Atoms will share in order to reach a stable electron configuration.

The Octet Rule

Atoms will gain or lose enough electrons to become isoelectronic with a noble gas.

Electron Dot Structure

A way to show the number of valence electrons in an atom.

Formula Unit

The lowest whole number ratio of ions.

Properties of Ionic Compounds

Ionic bonds are very strong.

Are solids at room temperature.

Have high melting and boiling points.

Empirical Formulas

The chemical formula for an ionic compound is arranged in the smallest whole number ratio.

Properties of Molecular Compounds

Much lower melting and boiling points. Is a solid, liquid, or gas at room temperature.

Structural Formula

A graphic representation that shows not only which atoms are present in a molecule.

Single bond

A chemical bond in which two atoms share one pair of electrons.

Double Bond

A type of covalent bond where two atoms share four electrons.

Triple Bond

A covalent bond where two atoms share three pairs of electrons.

Valence Shell Electron Pair theory

The electron pairs( both shared and unshared) in the outermost energy level try to get as far apart from each other as possible.

Linear shape

Occurs when atoms in a molecule are arranged in a straight line with a 180 degree bond angle.

Bent Shape

A non-linear molecular geometry where a central atom is bonded to two other atoms and features one or more lone pairs of electrons.

Trigonal Planar

A molecular geometry where a central atom connects to three surrounding atoms.

Pyramid shape

A molecular geometry where a central atom sits at the apex.

Tetrahedral shape

A central atom sits in the middle with four substituent atoms or groups pointing toward four corners.