YR 8 - Chemistry [Pure + Impure Substances] Flashcards
What are the physical states of matter?
The three physical states of matter are solids, liquids and gases.
What do the physical properties of a substance tell us?
The physical properties of a substance tells us its state (whether its a solid, liquid or gas).
What are the three properties of a substance?
The way a substance looks, feels or behaves is called a property of that substance.
What is the smallest particle of an element?
An atom is the smallest particle of an element.
What is an element?
An element is a substance made of one type of atom.
What is the periodic table?
The periodic table is a lost of the elements and their chemical symbols. Metals are on the left and centre and non-metals are on the right hand side of the periodic table.
What is a compound?
A compound is a chemical substance made of two or more different elements that are chemically joined together. E.g. When burnt, magnesium reacts with oxygen in the air to make magnesium oxide.
What is a mixture?
A mixture is made of two or more different elements or compounds that are not chemically bonded together.
How can mixtures be separated?
Mixtures can be separated by physical processes such as filtration, crystallisation, simple distillation, fractional distillation and chromatography.
What are some of examples of mixtures?
Examples of mixtures include air, sea water, iron and sulphur and solutions formed when a solute dissolves.
What can physical properties identify?
Physical properties can be used to identify a pure substance such as colour, odour, density, melting temperature, boiling temperature and solubility.
What is a solute?
A solute is the substance that dissolves in a liquid.
What is a solvent?
A solvent is the liquid that dissolves a solute.
What is a solution?
A solution is a mixture of a solute in a solvent. So solute + solvent = solution.
How do you know if a substance is soluble?
A substance is soluble if it is able to dissolve in a liquid.
How do you know if a substance is insoluble?
A substance is insoluble if it is unable to dissolve in a liquid.
What does the solubility of a substance refer to?
The solubility of a substance refers yo how well it dissolves.
What is crystallisation used for?
Crystallisation is used to obtain salt crystals like blue copper sulphate crystals by gently evaporating the water out of the solution.
Why does filtration work?
Filtration works because the insoluble solid particles are too large to go through the small holes on the filter paper.
What is the filtrate?
The filtrate is the liquid in the conical flask.
What is the residue?
Residue is the solid on the filter paper.
What is used in filtration?
Filter paper, funnel and conical flask are used during filtration.
What happens in evaporation?
The liquid evaporates into the air and turns into a gas in evaporation.
How can we use distillation?
Distillation can be used to separate a mixture of two or more liquids or a mixture of a soluble solid from a liquid.
