Bonding, Structure and properties of matter

Why do atoms form chemical bonds?

to gain a full outer shell, become stable

What is ionic bonding?

Occurs between metals & non metals

The electrostatic attraction between oppositely charged ions.

Dot and cross diagrams

Show only outer shell electrons

Giant Ionic Lattice structure

1 atom ionically bonded to many other metals and non metals

What is a property of ionic compounds related to melting and boiling points?

Ionic compounds have high melting and boiling points due to strong electrostatic attraction between ions.

When do ionic compounds conduct electricity?

Ionic compounds conduct electricity when molten or in aqueous solution.

Why do ionic compounds not conduct electricity in solid form?

In solid form, the particles in ionic compounds cannot move due to strong forces of attraction.

Are ionic compounds soluble in water?

Yes, ionic compounds are soluble in water.

What is covalent bonding?

Occurs between 2 nonmetal atoms, share electrons between 2 atoms

Types of covalent structures

Simple covalent and Giant covalent

Simple covalent molecular

Low mp & bp = weak intermolecular forces between molecules, less energy to break them

Doesn't conduct electricity = molecules neutral, no charge

Not soluble in water

Types of Giant covalent lattice

Diamond, Graphite, Graphene

DIAMOND giant covalent lattice

Each atom bonded to 4 others.

Very high mp & bp = strong covalent bonds, lots of energy to break.

Extremely hard = rigid network of strong covalent bonds

Doesn't conduct electricity = no free electrons

GRAPHITE giant covalent lattice

Each atom covalently bonded to 3 others.

Conducts electricity when solid = delocalised electrons between layers can move carrying electrical current.

Slippery = lubricant, bonds between layers weak so can slide

GRAPHENE giant covalent lattice

Conductor of electricity & heat = delocalised electrons can move.

Strong for substance = strong covalently bonded to 3 other atoms

Thin & flexible = 1 atom thick

Uses of GRAPHENE giant covalent lattice

Fleixble electronic currents, bullet proof vests, cancer treatments

Types of Fullerenes

Carbon nanotubes and Bucky Balls

Carbon nanotubes

Very strong, used to reinforce materials.

Conducts electricity and used in circuit boards

Bucky Balls

Very small, Large SA to volume ratio

Used to deliver drugs to cells & as a catalyst

What is metallic bonding?

Electrostatic attraction between lattice of positive ions & sea of electrons

Properties of metals

High mp & bp = electrostatic attraction between positive ions & sea of electrons.

Malleable = layers can slide

Conducts electricity = delocalised electrons carry charge

Conducts heat

Alloy

Mixture of two or more metals/elements

Properties of alloys

Hard, layers can't slide bc of different size atoms, resistant to corrosion

Nano particles

Greater SA to V ratio.

Smaller the size of particles, greater the surface area

Issues with nanoparticles

Vary small, can potentially get into the skin, can be toxic