A compound ion produced from carbonic acid by releasing protons.
Pharaoh Thutmose III defeated the rebellious coalition of Canaanite vassal states led by the king of Kadesh.
The Gaul city Alesia, defended by Vercingetorix, was besieged by the Roman forces of Julius Caesar in 52 BC.
Rotating a rectangle around its axes of symmetry or around its sides results in solids of revolution.
Simple harmonic motion can be considered to be the one-dimensional projection of uniform circular motion.
A transitional form between fish and tetrapods, or four-limbed vertebrates.
Woodwind instruments differ from brass instruments mainly in their reed.
The California Gold Rush started in 1848, near San Francisco.
Several European countries joined the conquest of the New World, making America a colourful continent.
Due to its design and location, the Opera House of the Australian city is one of the most extraordinary opera houses in the world.
Direct action pumps and suction pumps are among the simplest water pumps.
Plants are capable of converting inorganic substances (carbon dioxide and water) into organic sugar.
The Votive Church of Szeged, located on the Great Plains of Hungary, emerges from the buildings of the city's famous square, while the National Pantheon can...
In the battle fought at the shores of Hellas, Octavian won a decisive victory over Marcus Antonius.
The battle ended with the victory of William the Conqueror´s Norman army over the English.
The surface of a sphere consists of the set of points which are all at the same distance from a given point in space.
Calculating the volume of a sphere is possible using an appropriate cylinder and cone.
Amino acids that make up proteins are bound by peptide bonds.
One of the best known species of spiders, often kept as pets. Its bite is not fatal for humans.
Flat feet, or fallen arches, may cause a number of health problems.