Sulphur dioxide emission is the main cause of acid rains. It is an intermediate product in the production of sulphuric acid.
A yellow-green toxic gas with a strong odour, one of the halogens.
A solid, grey substance which sublimates when heated. Its solution in alcohol is called tincture of iodine, it is a disinfectant.
One of the hydrogen halides, a highly aggressive substance - it even attacks glass.
A compound ion generated when a proton is added to an ammonia molecule.
A colourless gas with a pungent odour, its solution in water is called hydrochloric acid.
A colourless, heavier-than-air gas, an intermediate in the production of nitric acid.
A white, crystalline compound that breaks down when affected by light.
Halogen elements are a group in the periodic table consisting of five chemically related elements, fluorine, chlorine, bromine, iodine, and astatine.
A white, crystalline compound which breaks down when exposed to light.
Common salt (or table salt) is one of the most important sodium compounds, indispensable for living organisms.
A light yellow compound formed in the reaction of silver nitrate and potassium iodide.
Potassium permanganate is used as a disinfectant.
A colourless, viscous liquid, a highly corrosive, strong acid used in several industrial processes.
Hypochlorite ions are formed when water is disinfected with chlorine.
A polymorphic compound, mostly found in the form of quartz.
An allotrope of oxygen, consisting of 3 oxygen atoms.
One of the oxides of sulphur, forms sulphuric acid with water.
One of the hydrogen halides, it is used for the production of alkyl bromides.
It is also used as a food additive, limescale and rust remover.