C3

C3

Development of the periodic table:
The early periodic table:
The periodic table of elements developed as an attempt to classify the
elements. It arranges them in a pattern according to their properties.
Early versions of the periodic table failed to take account of the fact that
not all the…

More about acids and bases:
Strong and weak acids/alkalis:
Acids in aqueous solutions produce H+ ions.
Alkalis in aqueous solutions produce OH- ions.
A strong acid or base in 100% ionised in water
A weak acid or alkali is only partially ionised in water.
An acid is a proton donor…

Water
Water and solubility:
Water evaporates from rivers, lakes and oceans and condenses to form
clouds, returning to the surface as rain.
Most ionic substances are soluble in water, but many covalent
compounds are not.
A saturated solution contains the maximum amount of solute that will
dissolve at that temperature.…

Energy calculations:
Comparing the energy produced by fuels:
When fuels and food react with oxygen, energy is released ­ this
reaction is exothermic.
A simple calorimeter can be used to compare the energy released by
different foods in a school chemistry lab
Energy changes in reactions:
In chemical reactions, energy…

Analysis:
Test for positive ions:
Group 1 and 2 metals can be identified in their compounds using flame
tests.
Sodium hydroxide solutions can be used to identify different metal ions,
depending on the precipitate that is formed
Ammonium ions produce ammonia when sodium hydroxide is added,
and the solution is…