1 Materials In Our World

Question 1

What are Materials

Answer 1

Substances used to make objects.

Question 2

What are elements

Answer 2

Substances that are made up of just one type of atom

Question 3

What are compounds

Answer 3

Pure substances made from one type of atom. Consist of more than one element in fixed proportions.

Question 4

Properties of metals

Answer 4

High testily strength, ductility, malleability, shiny lister, melting point, and thermal and electrical conductivity.

Question 5

What is an alloy

Answer 5

A mixture of metals or small amounts of non metals to improve its properties.

Question 6

Polymers

Answer 6

A material with molecular structure composed of repeating smaller units bonded together. Eg nylon or rubber like latex.

Question 7

Properties of polymers

Answer 7

Less dense, corrosion resistant, great insulators, and natural polymers are compatible with human tissue

Question 8

Ceramics

Answer 8

Inorganic solids containing metal, non-metals and metalloid elements held by ionic and covalent bonds.
Range from crystalline to amorphous.

Question 9

What are composite materials

Answer 9

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.

Question 10

What is nanotechnology

Answer 10

A branch of material science that investigates the design properties and applications of materials produced on nanoscale.

Question 11

What is nanoscale?

Answer 11

Any structure between 1-100 nanometers(1 billionth of a meter 10^-9)

Question 12

What are nanomaterials

Answer 12

Substances both natural and synthetic composed of nanoparticles.

Natural examples include spider silk, butterfly wings and gecko feet.

Question 13

What are fullerenes

Answer 13

3D structures formed by a network of nano carbon atoms.
Hexagonal fullerenes are called graphene.
Cylindrical fullerenes are carbon nanotubes.

Question 14

Nanoparticles

Answer 14

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.

Question 15

What’s sieving

Answer 15

Seperate mixtures of solids with different particle sizes by passing through a mesh, smaller particles will pass through, larger ones won’t.

Question 16

What’s filtration

Answer 16

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

Question 17

What are the 2 types of filtration

Answer 17

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.

Question 18

What is density

Answer 18

The measure of gas per unit of volume.

Question 19

Sedimentation and recantation

Answer 19

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.

Question 20

Separation funnels

Answer 20

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.

Question 21

Centrifugation

Answer 21

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.

Question 22

Evaporation

Answer 22

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.

Question 23

Distillation

Answer 23

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.

Question 24

Fractional distillation

Answer 24

A method used to separate miscible (can mix) liquids that have boiling points that are only slightly different from each other.

Question 25

Electrostatic separation

Answer 25

Objects with opposite electric charges, attract to each other. By using electrostatic forces, you can separate attracted solid particles from gases.

Question 26

Chromatography

Answer 26

Separates liquids or gases based on the different affinity for various materials present in the chromatography apparatus.

Question 27

What does immiscible mean?

Answer 27

Two liquids which do not mix/ don’t form a homogeneous mixture.