Common salt is dissolved by water: polar water molecules form a coat around the ions.
Knallgas is the mixture of hydrogen and oxygen. It will explode when ignited.
The solution of hydrogen chloride in water is called hydrochloric acid.
The dissolution of zinc in hydrochloric acid produces hydrogen gas.
Large-scale ammonia production requires high temperature and pressure and the presence of iron as a catalyst.
The Rosetta Stone helped to solve the mystery of hieroglyphics.
The length of the metal frameworks of bridges change when the temperature changes.
A sphere is the set of points which are all within the same distance from a given point in space.
The boundaries of tectonic plates can be seen on the seafloor.
A glacier is a large body of ice that forms from snow, and is in constant, slow motion.
Submarines had an important role in naval warfare as early as World War I.
In alkaline batteries electric current is generated by electrochemical reactions
DC motors consist of a permanent magnet and a coil within the magnet, with electric current flowing in it.
An important endocrine gland producing hormones that affect metabolism and the calcium balance of the body.
This animation demonstrates various types of cylindrical solids as well as their lateral surfaces.
Wind, as an external force, plays an important role in shaping coastal areas and steppes.
This animation demonstrates the components (vertices, edges, diagonals and faces) of the cube, one of the Platonic solids.
The dodo is an extinct species of birds that used to be native to the island of Mauritius. It has become the symbol of extinction.
The naval battle fought by the British Navy against the German Navy was the largest sea battle in World War I.
An exercise about the regular hexahedron built from unit cubes to help deepen your knowledge of cubes.