science education teaching

Acids Acids contain the element hydrogen in combination with other non-metal elements. For example, hydrochloric acid contains hydrogen and chlorine. When an acid is placed in water, the hydrogen breaks away from the other elements. Hydrogen breaks away very easily with strong acids and with difficulty with weak acids. Strong acids are corrosive and will destroy living tissue. Acids may be dilute or concentrated; dilute has few acid particles in a large volume of water and concentrated has a large number of particles in a smaller volume of water. Properties: • • • Sour taste Turn blue litmus red Conduct electricity Bases You can think of bases as the opposite of acids. Bases react with acids to produce water and a salt; this reaction is called neutralisation. Strong bases attack living tissue and cause serious burns. We say that strong bases are caustic. Bases that dissolve in water are called alkalis. Properties: • • • Taste bitter Turn red litmus blue Have a soapy or chalky feel