Unit 1 Topic 1 Elements Compounds And Mixtures Flashcards
Define Element
An element is a substance that consists of only one type of atom. Elements cannot be broken down into simpler substances by chemical means.
Define Compound
A compound is a substance that consists of two or more different elements chemically combined.
Define Atom
An atom is the simplest particle of an element that can exist on its own in a stable environment.
Define Molecule
A molecule is a particle that consists of two or more atoms chemically bonded together.
What does ‘diatomic’ mean?
Diatomic refers to elements which exist as molecules containing two identical atoms covalently bonded.
In a particle diagram, a pure substance has only…
All formations will look the…
In a particle diagram, a pure substance has only one kind of particle.
All formations will look the same.
A mixture has … kinds of particle
A mixture has two or more different kinds of particle.
Name two semi-metals.
Two semi-metals are silicon and germanium.
What is thermal conductivity?
Thermal conductivity is the ability to conduct heat.
Name a good thermal conductor.
Copper is a good thermal conductor.
What is electrical conductivity?
Electrical conductivity is the ability to conduct electricity.
Name a good electrical conductor.
Silver is a good electrical conductor.
Name a compound that does not conduct electricity.
Polythene is a compound that does not conduct electricity.
What is ductility?
Ductility is the ability to be drawn into wires.
Name a ductile element.
Copper is ductile.
Define malleability.
Malleability is the ability to be hammered into shape without breaking.
Name a malleable element.
Iron is a malleable element.
Define melting point.
The melting point is the temperature at which a solid changes to a liquid on heating.
Name an element with a high melting point.
Iron is an element with a high melting point.
Name an element with a low melting point.
Chlorine is an element with a low melting point.
Define sonority.
Sonority is the ability to ring when struck.
Name a sonorous alloy.
Brass is a sonorous alloy.
Define alloy.
An alloy is a metal made by combining two or more metallic elements.
Describe the melting point of metals.
The melting point of metals is high except group 1 metals which have low melting points.
Describe the electrical conductivity of non-metals.
The electrical conductivity of non-metals is poor except graphite which conducts electricity.
Describe the melting point of non-metals.
Non-metals have a low melting point except diamond and graphite which have high melting points.
Define Mixture.
A mixture consists of two or more substances mixed together which are usually easy to separate.
Define solute.
A solute is a solid that dissolves.
Define solvent.
A solvent is the liquid in which the solute dissolves.
What is a solution?
A solution is a mixture of the solute dissolved in the solvent.
Give two substances which are miscible.
Alcohol and water are miscible.
Give two substances which are immiscible.
Oil and water are immiscible.
What is filtration used to do?
Filtration is used to separate an insoluble solid from a liquid.
Draw the filtration diagram.
Labels: filter funnel, filter paper, residue, filtrate, conical flask.
What is Recrystallisation used to do?
Recrystallisation is used to separate a solute from a solution.
Draw the diagram for Recrystallisation.
Labels: evaporating basin, gauze, tripod, heatproof mat, solution, Bunsen burner
What technique could you use to separate salt from salt solution?
Recrystallisation could be used to separate salt from salt solution.
What is a separating funnel used for?
A separating funnel is used to separate immiscible liquids based on a difference between the densities of the two liquids.
In a separating funnel, the more dense liquid is…
In a separating funnel, the more dense liquid is the bottom layer.
Draw a labelled diagram of a separating funnel.
Labels: stopper, oil, water, tap, separating funnel
What does Dalton’s Atomic Theory suggest?
Dalton’s Atomic Theory suggests that everything is made of minute particles called atoms.
What is simple distillation used to do?
Simple distillation is used to separate a solvent from a solution (e.g. Water from salt solution) or to separate miscible liquids (e.g. Ethanol and water) based on a difference in their boiling points.
Study the diagram for simple distillation
Not required to draw, only label.
What is the purpose of anti-bumping granules?
Anti-bumping granules are placed in the flask to promote smooth boiling.
Where should the bulb of the thermometer be located?
The bulb of the thermometer should be located at the junction of the still head.
If a liquid is flammable, what should you use to heat the flask, instead of a Bunsen burner?
If a liquid is flammable, for example ethanol, a water bath should be used to heat the flask instead.
What is the boiling point of ethanol?
The boiling point of ethanol is 79 degrees Celsius.
What is fractional distillation used to do?
Fractional distillation is used to separate miscible liquids, crude oil, or liquid air based on a difference in boiling points and it is used on liquids with boiling points which are close together.
Define a Fraction
Distillations collected at different temperatures are called fractions.
Study the diagram for fractional distillation.
You don’t need to draw it, only label it.
What is magnetism used to do?
Magnetism is used to separate a magnetic substance from a non-magnetic substance.
Give an example of two substances which could be separated using magnetism.
Iron and sulphur are two substances which could be separated using magnetism.
How can we prove that a chemical reaction forms to create a new substance?
We can prove a chemical reaction creates a new substance, because when iron and sulphur react they form iron (II) sulphide which is not magnetic.
What does HPLC stand for?
HPLC = High Performance Liquid Chromatography.
What is the label on the y-axis for HPLC?
The y axis label for HPLC is Detector Signal
What is the label on the x axis for HPLC?
The label on the x axis for HPLC is retention time
Give advantages and disadvantages of HPLC
HPLC is faster and provides better separation than other chromatography methods, however it is expensive and requires trained staff.
What is mass spectronomy?
Mass spectronomy is a technique that measures the masses of the particles in a substance.
Mass spectronomy can be used with both…
Mass spectronomy can be used with both elements and compounds.
What is the y axis label on a mass spectrum?
The y axis label on a mass spectrum is Relative Abundance.
What is the x axis label on a mass spectrum?
The x axis label on a mass spectrum is Mass.
Look at how average RAM can be calculated from a mass spectrum.
E.g. Chlorine - popular
Give advantages and disadvantages of mass spectronomy.
The sample can be very small, however the equipment is expensive and trained staff are required to operate it.
