Flashcards
Atoms, elements, compounds and mixtures
Cards in this deck (17)
- 1what is an atoman atom is the smallest part of an element that can exist
- 2what is an elementan element is a substance that contains only one sort of atom
- 3what is a compounda compound contains an atom of two or more elements, which are chemically combined in fixed proportions
- 4what are compounds represented bythey are represented by a combination of numbers and chemicals symbols called a 'chemical formula'
- 5what do scientists use chemical formulas for-the different elements in a compound
-how many atoms of each element one molecule of the compound contains - 6whats the only way compounds can be separated into component elementsby chemical reactions or electrolysis
- 7in a equation what side are the reactants onleft hand side
- 8in a equation what side are the products onthe right hand side
- 9what is the total mass of the products of a chemical reaction always equal toits always equal to the total mass of the reactants. This is because no atoms are lost or made
- 10what is a mixturemixtures consist of two or more elements or compounds which are not chemically combined
- 11do the compounds of a mixture retain there own propertiesyes they do-e.g in a mixture of iron and sulphur, the iron is still magnetic and sulphur is still yellow.
- 12what is filtration and what is it used forfiltration is used to separate soluble solids from insoluble solids e.g a mixture of salt (soluble) and sand (insoluble) can be separated by dissolving the salt in water and then filtering the mixture by dissolving the salt in the water and then filtering the mixture
- 13what is crystillisation and what is it used forit is used to obtain a soluble solid from a solution e.g salt crystals can be obtained from a solution of salty water
1-the mixture is gently warmed
2-the water evaporates leaving crystals of puresalt - 14what is simple distillation used forit used to obtain a solvent from a solution
- 15write a method for the analysis and purification of water samples from different sources- use a ph probe or a suitable indicator to analyse the ph of the sample
-set up the equipment as shown
-heat a set volume to 100 degrees so that the water changes from liquid to gas
-the water collects in the condenser and changes state from liquid to gas .Collect this pure water in a beaker
-When all the water from the sample has evaporated measure the mass of solid that remains to find the amount of dissolved solids present in the sample - 16what is fractional distillation and what is it used forit is used to separate mixtures in which the components have different boiling points e.g oxygen and nitrogen can be obtained from air by fractional distillation because they have different boiling points
- 17what is chromotography and what is it used forit is used to separate different soluble, coloured components of a mixture e.g the different colours added to a fizzy drink can be separated by chromatography
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- GCSE chemistry new Flashcards on Atoms, elements, compounds and mixtures, created by ella stokes on 22/10/2017.
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- ella stokes
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