Chapter 1 Flashcards
What is matter?
Matter is anything that has mass and occupies space
What are elements?
An element is a substance made up of atoms with the same atomic number.
What are compounds?
A compound is a pure substance made up of different types of atoms combined in a fixed ratio.
What are mixtures?
A mixture is a substance made by physically mixing other substances together.
What does homogenous mean?
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.
What does heterogeneous mean?
Diverse or different
A heterogenous solution or substance posses two or more different types of phases in the one sample
Eg. Suspension
What is a pure substance?
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
What is a solution?
A solution is a homogenous mixture of a solute dissolved in a solvent
What is a solute?
A substance that dissolves in a solvent Eg sugar is solute when dissolved in water.
What is a solvent?
A solute is a substance- liquid.
That is able to dissolve a solute to a form of solution.
Eg water
What are materials?
A material is a substance that can be used to make objects
List the types of materials
Matter, Elements, Compounds, Mixtures, Metals, Polymers, Ceramics, Homogenous, Heterogenous, Solutions, Pure Substances
What are metals?
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.
What is a polymer?
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.
What is an alloy?
An alloy is a substance formed when other materials (carbon and other metals) are mixed in with a metal.
What is a ceramic?
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
What is a composite material?
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.
What is nanotechnology
Nanotechnology is a branch of materials science that investigates the design properties and applications of materials produced on the nanoscale.
What is the nano scale
The term nano scale refers to structures that are between 1-100 nanometers.
nanometer (nm) - 1 billionth of a metre (10^-9)
What are nano materials?
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
What are some example of nano materials
Carbon molecules
- Fullerenes - carbon nanotubes - graphene
- Bucky ball
What are nano particles
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
How to make nano particles?
Top down fabrication - big material chipped to small size
Bottom up fabrication - growing the required material atom by atom of molecule by molecule
Methods of separation by particle size
Sieving and filtration
Explain Sieving
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
Explain filtration
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
Filtrate vs residue
The residue is the solid collected in the filter paper
The filtrate the purified liquid collected
What is density
Density is the measure of mass per unit of volume of a substance.
Explain a method of separating by density - Separation funnels
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.
What are examples of separation by boiling point
Evaporation and Distillation
Explain evaporation
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.
Explain distillation
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.
Separation by electric charge
Electrostatic separation and magnetic separation
What is magnetic separation
Uses a magnet - materials with magnetic property are attached to opposing forces and therefore are separated
What is electrostatic separation?
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.
