Chemistry Chapter 2- Structure, bonding and the Properties of Matter

What are the 3 types of bonds

• Metallic bonds

• Ionic bonds

• Covalent bonds

What are the limitations of using a Dot-cross diagram

• They don't show the 3D arrangement of atoms

• They don’t show relative sizes

• They don’t show the extent of large structures like ionic lattices

What are the limitations of using a Ball and stick diagram

• Misrepresents atom sizes

• Misrepresents bond lengths

What is the empirical formula

The simplest, whole number ratio of atoms of each element in a compound

How are elements in metallic bonds arranged

They are arranged in a giant metallic lattice

What is Particle theory

The idea “all matter is composed of tiny indivisible particles too small to see”

Factors that affect the melting point of a substance

• Intermolecular forces

• Molecular size

• Molecular shape

What are the limitations of particle theory

Doesn’t take in account:

• The size of particles

• The shape of particles

• The space between particles

What does (l) mean when used in chemical equations

The element is in liquid form

What does (s) mean when used in chemical equations

The element is in solid form

What does (g) mean when used in chemical equations

The element is in gas form

What does (aq) mean when used in chemical equations

The element is in a state where it can dissolve in water

How do ionic compounds effect their properties

• Increase the melting/boiling point

• Makes the compound brittle

• Makes the compound only to conduct electricity and heat in its molten or aqueous state

How the structure of polymers affects their properties

The structure of polymers impacts their properties, by increasing:

• Strength

• Flexibility

• Transparency

• Resistance to heat and chemicals.

How the structure of giant covalent structures affects their properties

• Melting and Boiling points

• Hardness

How the structure of metals and alloys affects their properties

The structure of alloys impacts their:

• Strength and Hardness

• Malleability and Ductility

• Conductivity

• Corrosion resistance

Why are alloys good conductors

They contain delocalised electrons

Properties of graphite in terms of their structure and bonding

Carbon atoms form 3 covalent bonds with 3 other carbon atoms forming layers of hexagonal rings which have no covalent bonds between them

Properties of diamond in terms of their structure and bonding

• Each 4 carbon atoms make 4 strong covalent bonds with 4 other carbon atoms to give a rigid giant covalent structure

Properties of graphene in terms of their structure and bonding

A single layer of graphite that are one atom thick

What is the structure of fullerene

Hexagonal rings of carbon atoms joined by covalent bonds

What is the structure of Buckminsterfullerene

A spherical, cage-like structure consisting of 60 carbon atoms arranged in hexagons and pentagons, (resembles a football)

What is a carbon nanotube

A tube-shaped structure made of carbon atoms that is measured in nanometers.

What is the structure of a carbon nanotube

A hollow, cylindrical structure formed by rolling up a single layer of graphene into a seamless tube

What is a catalyst

A substance that speeds up a chemical reaction without being used up in the process

Uses for carbon nanotubes

• Medicine

• Cosmetics

• Fabrics

• Development of catalysts

Advantages/Disadvantages of using CNTs for medicine

Advantages:

• Tissue engineering- CNTs can be used as scaffolds for tissue regeneration and repair

Disadvantages:

• Lack of solubility- CNTs are not water-soluble, which can limit their use in certain applications

Advantages/Disadvantages of using CNTs for cosmetics

Advantages:

• UV Protection- CNTs can absorb and block UV radiation, making them potential ingredients in sunscreens.

Disadvantages:

• High cost production- Synthesising high-purity CNTs is expensive

Advantages/Disadvantages of using CNTs for fabrics

Advantages:

• Lightweight and Flexible- CNTs are ultra-lightweight, maintaining flexibility while enhancing performance

Disadvantages:

• Environmental concern- CNTs are not biodegradable

Advantages/Disadvantages of using CNTs for development of catalysts

Advantages:

• CNTs offer a high surface area, which provides more active sites for catalytic reactions

Disadvantages:

• Producing high-purity or functional CNTs can be expensive