5.2 Structure and Properties of Matter

Ionic compounds are formed between...

• metals and metals

• non-metals and non-metals

• metals and non-metals

Which of the following is an ionic compound?

• sodium chloride

• carbon dioxide

• calcium sulfide

• sulfur dioxide

Ionic compounds form giant ionic lattices. What forces hold the giant ionic lattices together?

• strong frictional forces between the surfaces of the atoms

• strong magnetic forces of attraction between the poles of ions

• strong electrostatic forces of attraction between oppositely charged ions

Why do ionic compounds have high melting and boiling points?

• Ability to dissolve in water but cannot dissolve in inorganic solvents.

• Presence of mobile ions which allow them to experience high melting points.

• Strong electrostatic forces of attraction which require large amounts of energy to overcome.

• Weak intermolecular forces of attraction which require little energy to overcome.

The following properties are all characteristics of ionic compounds EXCEPT

• high melting and boiling points

• soft

• crystal lattice structure

• conduct electricity when dissolved in water

Why do ionic compounds conduct electricity when they are molten or dissolved?

• Their ions are free to move / mobile.

• Their ions are held in fixed positions / immobile.

Covalent compounds have ____ melting and boiling points.

Write down three properties of covalent substances.