An exercise about the polarity of molecules.
An exercise about different types of bonds.
A solid, grey substance which sublimates when heated. Its solution in alcohol is called ´tincture of iodine´, it is a disinfectant.
An exercise about compound ions.
Used in the production of beryllium and as a catalyst.
One of the allotropes of phosphorus.
Atoms within hydrogen halides are bound by covalent bonds, forming polar molecules.
The presence of hydronium ions relative to hydroxide ions determines a solution´s pH.
One of the halogens, it may cause skin irritation.
The lightest halogen, a pale yellow-green, toxic gas, extremely reactive. Its best known compound is teflon.
Colourless, heavier-than-air gas with a pungent odour. It forms white fumes in moist air.
A compound ion formed when a phosphoric acid molecule releases a proton.
One of the raw materials of traditional photography.
A compound ion, the main source of nitrogen for plants.
A compound ion produced when sulphuric acid releases protons.
A compound ion formed when a water molecule releases a proton.
Colourless, odourless, lighter-than-air gas. The most common chemical element in the universe.
Water is a very stable compound of hydrogen and oxygen, vital for all known forms of life. In nature it occurs in liquid, solid and gaseous state.
Ammonia is a colourless gas with a characteristic pungent smell. Its solution in water is called ammonium hydroxide or household ammonia.
An odourless, yellow, solid substance, the 16th most common in the Earth´s crust. One of the best known sulphur compounds is pyrite, also known as ´fool´s...