2. Bonding, Structure and the Properties of Matter

What are the 3 types of strong chemical bonds?

Ionic, covalent, and metallic bonds.

What type of elements form ionic bonds?

Metals and non-metals.

What type of elements form covalent bonds?

Non-metals with other non-metals.

What type of elements form metallic bonds?

Metals with metals (or in alloys).

How do metal atoms form ions?

They lose electrons to form positive ions.

How do non-metal atoms form ions?

They gain electrons to form negative ions.

What is the charge on Group 1, 2, 6 and 7 ions?

Group 1: +1, Group 2: +2, Group 6: –2, Group 7: –1.

What is an ionic bond?

The electrostatic force between oppositely charged ions.

What structure do ionic compounds form?

Giant ionic lattice.

Why do ionic compounds have high melting and boiling points?

Due to strong electrostatic forces between ions.

When do ionic compounds conduct electricity?

When molten or dissolved in water (ions can move).

What is a covalent bond?

A shared pair of electrons between atoms.

What types of substances have covalent bonds?

Small molecules, polymers, and giant covalent structures.

Give 3 examples of simple covalent molecules.

H₂, HCl, CH₄.

Give 3 examples of giant covalent substances.

Diamond, graphite, silicon dioxide.

Why do simple molecular substances have low boiling points?

Because of weak intermolecular forces.

Why do giant covalent substances have high melting points?

Because all atoms are bonded by strong covalent bonds.

Do simple molecular substances conduct electricity? Why/why not?

No, they have no overall charge or free electrons.

What is a polymer?

A very large molecule made by joining many monomers.

Why are polymers usually solids at room temperature?

Because of relatively strong intermolecular forces.

How are the atoms arranged in metals?

Giant structures of atoms in regular layers.

What is metallic bonding?

Attraction between positive metal ions and delocalised electrons.

Why are metals good conductors?

Because of delocalised electrons that carry charge and heat.

Why are alloys harder than pure metals?

Different sized atoms distort the layers, preventing them from sliding.

What are the 3 states of matter?

Solid, liquid, ga