1 Materials In Our World Flashcards
What are Materials
Substances used to make objects.
What are elements
Substances that are made up of just one type of atom
What are compounds
Pure substances made from one type of atom. Consist of more than one element in fixed proportions.
Properties of metals
High testily strength, ductility, malleability, shiny lister, melting point, and thermal and electrical conductivity.
What is an alloy
A mixture of metals or small amounts of non metals to improve its properties.
Polymers
A material with molecular structure composed of repeating smaller units bonded together. Eg nylon or rubber like latex.
Properties of polymers
Less dense, corrosion resistant, great insulators, and natural polymers are compatible with human tissue
Ceramics
Inorganic solids containing metal, non-metals and metalloid elements held by ionic and covalent bonds.
Range from crystalline to amorphous.
What are composite materials
A combination of 2 or more distinct materials with significantly different physical and chemical properties resulting in a material with a range of properties. Eg concrete.
What is nanotechnology
A branch of material science that investigates the design properties and applications of materials produced on nanoscale.
What is nanoscale?
Any structure between 1-100 nanometers(1 billionth of a meter 10^-9)
What are nanomaterials
Substances both natural and synthetic composed of nanoparticles.
Natural examples include spider silk, butterfly wings and gecko feet.
What are fullerenes
3D structures formed by a network of nano carbon atoms.
Hexagonal fullerenes are called graphene.
Cylindrical fullerenes are carbon nanotubes.
Nanoparticles
Usually spherical particles with diameter of 1-100 nm
Can be different from the bulk materials they’re made of.
Can travel through air, skin and cells making them potentially harmful.
What’s sieving
Seperate mixtures of solids with different particle sizes by passing through a mesh, smaller particles will pass through, larger ones won’t.
What’s filtration
Used to seperste solids from liquid or gas by filter paper.
The purified liquid or gas is called filtrate. The solid collected is known as the residual
What are the 2 types of filtration
Gravitational filtration
Uses the weight of solid-liquid mixture to push the mixture through filter paper which is in a funnel shape.
Vacuum filtration
The solid liquid mixture poured into a funnel is sucked into a vacuum tube and the solid residue is trapped by filter paper.
Faster than gravitational and drys the residue faster.
What is density
The measure of gas per unit of volume.
Sedimentation and recantation
Sedimentation
The sediments will settle after some time leaving the liquid on top and sediment solids on the bottom.
Decanting
You can now separate the mixture by pouring the liquid on top out.
Not very effective because fine solid particles will stay floating in the liquid.
Separation funnels
If 2 liquids have different densities and are immiscible (don’t mix) they can be seperated through a separation funnel.
If a tap is put on the base of a beaker, the liquid which is more dense will pour out first, separating the liquids.
Centrifugation
Spinning a liquid mixture rapidly to speed up sedimentation and extract finer particles that won’t seperate naturally, denser particles are pushed to outside of container by centrifugal forces.
Evaporation
Liquid is evaporated while solid is left behind.
Solids can dissolve in liquids to form solutions; the solid is a solute and liquid is solvent.
Distillation
The solution is heated in a flask which vaporises the liquid, this vapour is then passes through or condenser which cools the Vapor turning it back into a liquid. This liquid is called a distillate.
Fractional distillation
A method used to separate miscible (can mix) liquids that have boiling points that are only slightly different from each other.
Electrostatic separation
Objects with opposite electric charges, attract to each other. By using electrostatic forces, you can separate attracted solid particles from gases.
Chromatography
Separates liquids or gases based on the different affinity for various materials present in the chromatography apparatus.
What does immiscible mean?
Two liquids which do not mix/ don’t form a homogeneous mixture.
