Chapter 2

Covalent Bond

A bond formed when atoms share one or more pairs of eleetrons.

Molecule

A group of atoms that are held together by chemical forces; a molecule is the smallest unit of matter that can exist by itsels and retain all of substance's chemical properties.

Compound

A substance made upmof atoms of two or more different elements joined by chemical bonds.

Element

A substance that cannot be separated or broken down into simpler substance by chemical means; all atoms of an element have the same atomic number.

Ion

An atom, radical, or molecule that has gained or lost one or more electrons and has a negative or postive charge.

Ionic Bond

The attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another.

Hydrogen Bond

The intermolecular force occuring when a hydrogen atom tht is bonded to a highly electrogative atom ofmone molecule is attracted to two unshared electrons of another molecule.

Atom

The smallest unit of an element that maintains the chemical properties of that element.