GCSE Bonding

Ion

Formed when an atom loses or gains electrons

Ionic Compound

Bonding of a metal and non-metal atom bonding

Molecule

2 or more atoms chemically joined together

How do simple molecules form?

Bu covalent bonding between non-metal bonding

What do ionic substances look like?

Crystal-cubic shape

Properties of ionic substances?

• High boiling point

• Hight melting point

• Conducts electricity

Why can ionic substances conduct electricity in the molten state?

Ions can carry charge throughout the substance

Why do ionic substances look like this?

Regular 3D ionic lattice with strong bonds between them

How does a Mg atom become a Mg^2+ ion?

Loses 2 electrons

How does a Cl atom become a Cl- ion?

Gains 1 electron

How is NaCl formed?

Na- Loses 1 electron (Na+)

Cl- Gains 1 electron (Cl-)

What is the structure of an ionic compound?

Giant 3D lattice structure held together by strong oppositely charged ions

Why do ionic structures not conduct electricity in the solid state?

Fixed electrons

Why do ionic substances have high melting and boiling points?

Strong electrostatic forces that require a large amount of energy to break

What is the structure of a simple covalent molecule?

Strong covalent bonds between non-metal atoms with weak intermolecular forces between the molecules

What are the simple covalent molecules on the spec?

• Chlorine (Cl2)

• Methane (CH4)

• Oxygen (O2)

• Ammonia (NH3)

• Nitrogen (N2)

• Hydrogen (H2)

• Hydrogen Chloride (HCl)

• Water (H2O)

What do simple covalent substances look like?

Weak forces between molecules

What are the properties of simple covalent substances?

• Low melting point

• Don’t conduct electricity

Why do simple covalent substances have low melting and boiling points?

Weak forces that require little energy to break

What are the giant covalent substances on the spec?

• Diamond

• Graphite

• Silicon dioxide

• Fullerenes

• Graphene

• Polymers

What is the structure of graphite?

Layers of hexagonal rings held together by weak intermolecular forces.

1 carbon atom bonded to 3 others

Why is graphite slippery?

Weak forces are easily broken

Why does graphite have a high melting point?

Strong covalent bonds that require a lot of energy to break

Why does graphite conduct electricity?

Free electron from each carbon atom that can carry charge throughout the structure

What are fullerenes?

Carbon atoms in the shape of cages/ balls/ tubes

What is the structure of diamond?

Carbon atoms held together by strong covalent bonds between the atoms. Each atom is bonded to 4 others in a giant lattice structure

What is the structure of silicon dioxide?

Carbon atoms held together by strong covalent bonds between the atoms. Each atom is bonded to 4 others in a giant lattice structure

Why is diamond hard?

Strong bonds between the atoms meaning lots of energy is needed to break and there is a lot of bonds that need to be broken

Why does diamond have a high melting point?

Strong bonds between the atoms meaning lots of energy is needed to break and there is a lot of bonds that need to be broken

Why does silicon dioxide have a high melting point?

Strong bonds between the atoms meaning lots of energy is needed to break and there is a lot of bonds that need to be broken

Why does diamond NOT conduct electricity?

No free electrons/ ions to carry charge

Why does silicon dioxide NOT conduct electricity?

No free electrons/ ions to carry charge

What is the structure of a metal?

Lattice of metal ions (+) surrounded by a sea of charged electrons (-)

Why are metals malleable?

Layers of atoms can slide over each other

Why do metals have a high melting point?

Electrostatic forces between ions (+) and electrons (-) are strong

What are alloys?

Made from a mixture of elements (at least 1 is a metal)

Why are metals usually harder than the pure metal itself?

Different atoms have different sizes that disrupts the structure and makes it more difficult for the layers to slide over each other