Post on 31-Dec-2015
description
A compound is two or more different elements(atoms) bonded together.
Elements are rarely found in their pure form because they have unstable valences. They are always trying to fill or be left with a full valence of 8 electrons.
When elements form compounds their properties change. Like Na (explosive) and Cl (deadly) combine to make salt.
A chemical formula describes the type of elements and the number of atoms in a substance.
The subscript tell how many atom of eachelement are in a substance.
Ionic bond
Covalent bond
Metallic bond
The valence electrons are shared ina metallic bond.
In an ionic bond valence electrons are transferred between atoms.
Atom are attracted in ionic bonds because positive and negative ions are created and opposites attract.
The net charge of an ionic compound will be neutral or no charge.
positive
positive
positive
negative
negative
negative
Neutral or no charge
No