Chemistry 2

Ionic Bonding

If it lost an electron it has a positive charge

If it gained an electron it has a negative charge

The element would lose or gain an electron to get a full outer shell

It is now an ion

A Metal loses an electron to a non-metal

Covalent Bonding

The share electrons

Occurs between non-metal atoms

Atoms are unstable - not got a full outer shell

Simple Covalent Molecules

Low melting and boiling points because of their weak forces

Strong covalent bonds within molecules

No overall charge

Don't conduct electricity

Metals have free electrons which means that electricity can flow

Making Salts

Metal Oxide + Acid makes a salt and water

Metal + Acid makes a salt + hydrogen

Test for Hydrogen - Collect the gas in a test tube and pur a lighted plint in the test tube. If you hear a ssqeaky pop it's hydrogen

Electrolysis

Alkali + Acid makes a salt

Metal Carbonate + Acid makes a salt +carbon dioxide and water

"Splitting up using electricity"

Test for CO2 - Put a just extinguished splint in a test tube full of the gas and if it lights up again its CO2

We use an electric current to break down or decompose a substance made of ions.

pH scale - weak/strong acids or alkalis