Material Choices (OCR)

Material properties

Information about ____________ helps in choosing the best material for a product.

Property

A characteristic of a material that describes its behavior.

Ceramics

Materials made from clay, which is hardened by heating.

Hard

Resistant to scratching.

Weak in tension

Break easily when pulled or stretched.

Brittle

Snap rather than bend when stressed.

Metals

Elements that readily lose electrons to form positive ions.

Malleable

Can be shaped without breaking.

Ductile

Can be drawn into wires.

Polymers

Large molecules made up of repeating smaller units called monomers.

composite material

A _____________ is a combination of two or more materials with different properties.

Reinforcement

The material that provides strength and stiffness.

Matrix

The material that binds the reinforcement together.

FRP

Plastics reinforced with fibers like glass, carbon, or aramid. Used in various applications due to their high strength-to-weight ratio.

Wood

A natural composite of cellulose fibers embedded in a lignin matrix.

Use

The application or purpose of a material.

Tensile Strength

Measures a material's ability to resist being pulled apart.

Compressive Strength

Measures a material's ability to resist being crushed.

Alloy

A mixture of two or more elements, where at least one element is a metal.

lattice

Pure metals have a regular arrangement of atoms (______).

deform

When a force is applied, atoms can slide past each other, causing the metal to ______.

Mild steel

Easily shaped for car body parts. Susceptible to rust but can be protected by galvanizing and painting.

Aluminum

A lightweight metal with excellent corrosion resistance due to a protective oxide layer.

Aluminum foil

Used for food packaging because it's malleable, non-reactive, and lightweight.

Copper

_______ and brass excel in electrical conductivity and corrosion resistance.

Gold

A soft, malleable, and highly unreactive metal.

Initiation

Substance splits into two parts with unpaired electrons (free radicals).

Propagation

New free radical reacts with another monomer, adding two carbon atoms to the chain.

Termination

Two free radicals combine, forming a covalent bond and ending chain growth.

Functional groups

These are specific groups of atoms within a molecule that determine its chemical properties and reactivity.

Isomers

Molecules with the same molecular formula but different structural arrangements. This leads to different properties and characteristics.

Hydrocarbons

Organic compounds containing only carbon and hydrogen atoms. Examples include alkanes, alkenes, and alkynes.

Reaction Mechanism

The step-by-step process of how organic reactions occur.

Stereoisomerism

Molecules with the same molecular formula and structural connectivity but different spatial arrangements.

Allotropes

Different structural forms of the same element (e.g., diamond, graphite, and fullerene for carbon).

Graphene

Potential applications are Electronics, materials science, energy storage due to its exceptional conductivity and strength.

Nanotubes

Potential applications in electronics, materials science, and medicine due to their high strength and conductivity.

Buckyballs

Potential applications in medicine (drug delivery), electronics, and materials science.

Carbon fibers

Another allotrope of carbon, used in reinforced composites due to their high strength-to-weight ratio.

Graphene oxide

A derivative of graphene with oxygen-containing functional groups, used in various applications including water filtration and electronics.

Electrolytes, temperature, and surface area

Factors Affecting Rusting

Coating

Applying paints, varnishes, or oils to create a barrier between the metal and the environment.

Galvanization

Coating iron with a layer of zinc, which acts as a sacrificial anode.

Alloying

Creating alloys with increased corrosion resistance (e.g., stainless steel).

Oxidation states

Assigning oxidation numbers to elements to track electron transfer.

Balancing redox equations

Using methods like the half-reaction method or the oxidation number method.

Life-cycle assessment

An analysis of a product's environmental impact.

Wooden chair

Low Impact: _____ (unless cleaning or repair is needed)

Car

High Impact: ___

Recycling

Consumes energy and produces waste but conserves resources.