Structure, bonding and the properties of matter

The properties of matter include an object's density, color, mass, volume, length, malleability and ability to change its chemical composition, according to the University of California, Davis. Scientists define matter as any object that contains molecules and is capable of taking up space.

Structure and bonding. Elements are held together in different ways and the properties of chemical compounds are determined by the bonding between atoms and the attractive intermolecular forces between molecules.

Ionic Covalent Metallic This bonding occurs in: compounds from metals combined with non-metals  compounds of non-metals combined with non-metals and in most non-metallic elements  metallic elements and alloys  In this bonding the particles are: oppositely charged ions  atoms that share pairs of electrons  atoms that share electrons that move about.

Covalent bonds

Ions are electrically charged particles formed when atoms lose or gain electrons. They have the same electronic structures as noble gases.

Metal atoms form positive ions, while non-metal atoms form negative ions. The strong electrostatic forces of attraction between oppositely charged ions are called ionic bonds.

Ions are electrically charged particles formed when atoms lose or gain electrons. This loss or gain leaves a complete highest energy level, so the electronic structure of an ion is the same as that of a noble gas - such as a helium, neon or argon.

they go in opposite directions when they ionise:

• Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions
• Non-metal atoms gain an electron, or electrons, from another atom to become negatively charged ions

A covalent bond is a strong bond between two non-metal atoms. It consists of a shared pair of electrons. A covalent bond can be represented by a straight line or dot-and-cross diagram.

Hydrogen and chlorine can each form one covalent bond, oxygen two bonds, nitrogen three, while carbon can form four bonds.

I will need to understand what covalent bonding is, and to remember some of the properties of molecules that are formed in this way.

A covalent bond forms when two non-metal atoms share a pair of electrons. The electrons involved are in the highest occupied energy levels - or outer shells - of the atoms. An atom that shares one or more of its electrons will complete its highest occupied energy level.

Covalent bonds are strong - a lot of energy is needed to break them. Substances with covalent bonds often form molecules with low melting and boiling points, such as hydrogen and water.

After bonding, the chlorine atom is now in contact with eight electrons in its highest energy level - so it is stable. The hydrogen atom is now in contact with two electrons in its highest energy level - so the hydrogen is also stable.