Metal atoms form a regular lattice structure.
A liquid-crystal display utilises the light modulating properties of liquid crystals.
Cinemas were built in large numbers in big cities of the US in the 1910s.
This animation presents the states and state capitals of Germany
Machines powered by animals were mainly used in mills, for grinding grains.
These tools, revolutionary even in their simplicity, are still in use today.
The dentition of different species of mammals reflect their feeding habits.
A type of prehistoric reptile having bony plates on its back, which aided thermoregulation.
The Arctic tern is famous for its long migration route: it flies from the Arctic to the Antarctic and back again each year.
The battle of the Greek-Persian War became famous for the heroic sacrifice of the Spartan soldiers.
This animation demonstrates various types of cylindrical solids as well as their lateral surfaces.
The most important Neoclassicist building in France, completed in 1791, became the final resting place of many of France´s greats.
Jamestown, founded in 1607, was the first permanent English settlement on the east coast of North America.
The limbic system plays an important role in forming emotions and in learning.
Pearls, often used as gemstones, are the by-products of certain molluscs' protective mechanisms.
During the evolution of vertebrates the relative development of brain areas has changed.
Ancient Egypt was called the ‘gift of the Nile’, since the river played an important role in the rise of Egyptian civilisation.
The Apache attack helicopter, named after an American Indian tribe, was developed for the United States Army.
Limestone is a widely and diversely used material.
During the substitution reaction the hydrogen atoms of methane are substituted with chlorine atoms, the by-product is hydrogen chloride.