Ionic and covalent compounds

Question 1

True or False

Ionic substances conduct electricity when melted or dissolved in water.

Answer 1

True

Question 2

What is a covalent bond?

Answer 2

A covalent bond is a chemical link between two atoms in which electrons are shared between them.

Question 3

How do ionic bonds form?

Answer 3

Ionic bonds form when a metal reacts with a non-metal. Metals form positive ions; non-metals form negative ions. Ionic bonds are the electrostatic forces of attraction between oppositely charged ions.

Question 4

What are two properties of ionic compounds?

Answer 4

1. High melting and boiling points - Ionic bonds are very strong - a lot of energy is needed to break them. So ionic compounds have high melting and boiling points.
2. They are Conductive when liquid (only when dissolved in water or melted).

Question 5

What are the two main types of covalently bonded substances?

Answer 5

1. simple molecules
2. giant covalent structures.

Question 6

What is a simple molecule?

Answer 6

A simple molecule only contains a few atoms held together by strong covalent bonds.

Question 7

What is a giant covalent structure?

Answer 7

Giant covalent structures contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds. The atoms are usually arranged into giant regular lattices extremely strong structures because of the many bonds involved.

Question 8

What are the properties of giant covalent structures?

Answer 8

1. Very high melting points because a lot of strong covalent bonds must be broken.
2. Variable conductivity

Question 9

What are the properties of simple molecular substances?

Answer 9

1. Low melting and boiling points - This is because the weak intermolecular forces break down easily.
2. Non-conductive - This is because they do not have any free electrons or an overall electric charge.