Topic - Bonding

What are ions?

Charged particles - they can be single atoms or groups of atoms

What happens when metals form ions?

They lose electrons from their outer shell to form positive ions

What happens when non-metals form ions?

They gain electrons into their outer shell to form negative ions

What type of bonding happens when non metal + metal happens?

Ionic bonding

Why are non metals and metals particular attracted together?

Strong electrostatic forces between the oppositely charged ions. This attraction is called an ionic bond.

Which groups are the most likely to form ions?

Group 1 +2 and Group 6 +7

Advantages of dot and cross diagrams?

1. Show which atom the electrons in an ion originally came from

2. Show the arrangements in an atom or ion

3. Don’t show the structure of the compound

4. Don’t show the size of the ions or how they’re arranged

MAKE SURE TO UNDERSTAND DOT AND CROSS DIAGRAMS

YES OR NO?

What is the structure of ionic compounds?

Have a structure called a giant ionic lattice

Why do ionic compounds have ions closely packed together in a regular lattice arrangement?

As there are very strong electrostatic forces of attraction between the oppositely charged ions, in all direction in the lattice.

How can a lattice be represented?

The ball and stick model

Properties of ionic compounds?

1. High melting/boiling points

2. When they’re solid - the ions are held in place so they can’t conduct electricity

3. When they melt the ions are delocalised so they can conduct electricity/heat

4. Some ionic compounds dissolve easily in water.

What type of bond form when non-metals react together?

Covalent bonds

What makes covalent bonds so strong?

The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces

MAKE SURE YOU KNOW HOW TO DO THE DOT AND CROSS DIAGRAMS FOR COVALENT BONDING

YES OR NO?

Explain why molecules using covalent bonds have a low boiling and melting point

Even tho the atoms within these molecules are held by strong covalent bonds - the forces of attraction between these molecules are very week. SO you need to break these feasible intermolecular forces take doesn’t require a lot of energy.

Properties of simple molecular substances that use covalent bonding?

1. Low melting and boiling point - gases or liquid at room temp

2. Don’t conduct electricity because they aren’t charged.