Chemical reactions
A chemical reaction is a change that takes place when one or more substances (called reactants) form one or more new substances (called products)
Evidence of chemical reaction
colour change
precipitate
energy being produced (fizzing, burning)
odour being produced
total mass and number of each atom type don’t change
State symbols
solid - (s)
liquid - (l)
gas - (g)
dissolved in water - (aq)
Sequential reactions
sometimes the product of a reaction can the go on and be consumed in a subsequent reaction