Chapter 1

Question 1

What is matter?

Answer 1

Matter is anything that has mass and occupies space

Question 2

What are elements?

Answer 2

An element is a substance made up of atoms with the same atomic number.

Question 3

What are compounds?

Answer 3

A compound is a pure substance made up of different types of atoms combined in a fixed ratio.

Question 4

What are mixtures?

Answer 4

A mixture is a substance made by physically mixing other substances together.

Question 5

What does homogenous mean?

Answer 5

Uniform. The components of a homogenous substance are uniformly distributed throughout the substance.

Eg. A solution where the solute and the solvent cannot be differentiated.

Question 6

What does heterogeneous mean?

Answer 6

Diverse or different
A heterogenous solution or substance posses two or more different types of phases in the one sample

Eg. Suspension

Question 7

What is a pure substance?

Answer 7

Pure substances are defined as substances that are made of only one type of atom or only one type of molecule (a group of atoms bonded together)

Eg, metals , particular gases Eg h2

Question 8

What is a solution?

Answer 8

A solution is a homogenous mixture of a solute dissolved in a solvent

Question 9

What is a solute?

Answer 9

A substance that dissolves in a solvent Eg sugar is solute when dissolved in water.

Question 10

What is a solvent?

Answer 10

A solute is a substance- liquid.
That is able to dissolve a solute to a form of solution.
Eg water

Question 11

What are materials?

Answer 11

A material is a substance that can be used to make objects

Question 12

List the types of materials

Answer 12

Matter, Elements, Compounds, Mixtures, Metals, Polymers, Ceramics, Homogenous, Heterogenous, Solutions, Pure Substances

Question 13

What are metals?

Answer 13

Metals are valuable materials found in the natural environment.
They have a useful set of properties such as high tensile strength, ductility , malleability, shiny lustre, high melting points and thermal and electrical conductivity.

Native metals: naturally found in their elemental metallic form Eg gold and copper
Most metals are found as compounds known as minerals which make up ores mined from the earths crust.

Question 14

What is a polymer?

Answer 14

A polymer is a material with a molecular structure that is composed of many repeating smaller units bonded together.

Eg synthetic; plastics such as polystyrene, (polythene), nylon and rubbers such as latex.
Eg. Natural; cotton, silk and paper.

Properties = less dense, corrosion resistant, electrical resistance and compatible human tissue.

Question 15

What is an alloy?

Answer 15

An alloy is a substance formed when other materials (carbon and other metals) are mixed in with a metal.

Question 16

What is a ceramic?

Answer 16

Material that is produced by the firing (heating followed by cooling) of clay.

• inorganic and non-metallic solid - contains metals, none metals and metalloids elements held together by ionic and covalent bonds.
• can be organised to not organised

Question 17

What is a composite material?

Answer 17

A combination of two or more distinct materials with significantly different physical and chemical properties.
It demonstrates a range of properties by using one of the individual materials.

Eg Reinforced concrete - concrete matrix embedded steeled bars
- low tensile strength of concrete (ceramic) is counteracted by the high tensile strength of steel, alloy, while maintaining the high compressive strength of the concrete.

Question 18

What is nanotechnology

Answer 18

Nanotechnology is a branch of materials science that investigates the design properties and applications of materials produced on the nanoscale.

Question 19

What is the nano scale

Answer 19

The term nano scale refers to structures that are between 1-100 nanometers.
nanometer (nm) - 1 billionth of a metre (10^-9)

Question 20

What are nano materials?

Answer 20

Nano materials are substances (natural and synthetic), that are composed of single units that exits on the nano scale.

Eg. Gold,
Gecko feet, spider silk and butterfly wings

Question 21

What are some example of nano materials

Answer 21

Carbon molecules

• Fullerenes - carbon nanotubes - graphene
• Bucky ball

Question 22

What are nano particles

Answer 22

Nano particles usually are spherical shaped particles that exist on the nanoscale.

The optical properties are markedly different from the bulk material
Eg gold ; yellow lustre - pinky red colour

Question 23

How to make nano particles?

Answer 23

Top down fabrication - big material chipped to small size

Bottom up fabrication - growing the required material atom by atom of molecule by molecule

Question 24

Methods of separation by particle size

Answer 24

Sieving and filtration

Question 25

Explain Sieving

Answer 25

Sieving is a method used to separate a mixture of solids with different particles. The techniques involves the particles of pass through a mesh. Particles which are larger are left behind in the mesh device.

Eg baking, mining

Question 26

Explain filtration

Answer 26

Filtration is a separation method used to separate solid particles from a liquid or gas.

In labs filter paper is used to separate liquids from solids.

Eg. Vacuum cleaners

Question 27

Filtrate vs residue

Answer 27

The residue is the solid collected in the filter paper

The filtrate the purified liquid collected

Question 28

What is density

Answer 28

Density is the measure of mass per unit of volume of a substance.

Question 29

Explain a method of separating by density - Separation funnels

Answer 29

Two liquids with different densities are immiscible (don’t mix), then the liquids can be separated with a separation funnel.

A separation funnel is a glass flask connected to a thin outlet tube with a small tap. When the mimicked liquid are put in the top flask layers will form and - less dense at top, dense at the bottom. Open tap, denser liquid will flow first and is separated from less dense liquid

Eg oil and water.

Question 30

What are examples of separation by boiling point

Answer 30

Evaporation and Distillation

Question 31

Explain evaporation

Answer 31

Solids that have dissolved in the solvent can be separated from the liquid by boiling off and evaporating the liquid. Then the solid can be recovered.

Question 32

Explain distillation

Answer 32

Distillation is a way of separating two liquids with the same density through an apparatus. The solution is heated in a distillation flask to vaporise liquid. Vapour passes through a condenser, which is a tube which cooled with running water cooling the water vapour causing it to condense back to liquid and from droplets. The condensed liquid drips out of the condenser into receiving flask - distillate is the liquid collected.

Question 33

Separation by electric charge

Answer 33

Electrostatic separation and magnetic separation

Question 34

What is magnetic separation

Answer 34

Uses a magnet - materials with magnetic property are attached to opposing forces and therefore are separated

Question 35

What is electrostatic separation?

Answer 35

The electrostatic method separates particles of different electrical charges. When particles of different polarity are brought into an electrical field, they follow different motion and can be caught separately.