Elements and their use

a. chlorine

- For water purification

- disinfectant

- bleach

- PVC plastic raw materials

b. calcium

- cement

- insecticides

- carbide

- Chalk

- Food additives

- Not the raw material of fireworks

c. potassium

- fertilizer

- Manufacture of soap

- Processing of mirror glass

d. sulfur

- Lighters

- Powder machine

- Drugs

- Volcanism rubber

- Not photography

e. phosphorus

- Match (red phosphorus)

- The weapons (white phosphorus)

- Detergents.