Elments, Compounds And Mixtures Flashcards
What are all substances made of ?
Atoms
What is an atom ?
An atom is the smallest part of an element.
What elements to the following symbols represent ?
O
Na
C
O= oxygen
Na= sodium
C= carbon
Approximately how many elements are there ?
100 - 118
The answer is 118
What does the periodic table show ?
The elements, arranged in order of atomic number.
How are compounds formed ?
Two or more elements chemically bonding with each other.
What always happens in a chemical reaction ?
One or more substances are formed.
How can chemical equations be presented ?
With equations.
What is a mixture ?
Two or more elements which aren’t chemically bonded.
Are the chemical properties of each individual substance changed when they are in a mixture ?
No.
Name 5 physical processes that can be used to separate mixtures ?
Distillation, filtration, evaporation, crystallisation and chromatography.
Describe the process of filtration and give an example of where this might be used ?
A liquid is separated from an insoluble solid through filter paper. E.g. Seperating sand from salt water.
Describe the process of crystallisation and give an example of where this might be used ?
A crystal is obtained from solution by evaporating of the liquid (solvent). E.g. making copper sulphate crystals.
Describe the process of simple distillation and give an example of where this might be used ?
A liquid is obtained from solution by evaporating it off and then condensing it. E.g. obtaining pure water from a salt solution.
Describe the process of fractional distillation and give an example of where this might be used ?
A mixture of liquids is heated, evaporated and then condenses at different temperatures. E.g. Seperating fractions from crude oil.
