The German liquid-propellant rocket, developed during WWII, was the first known man-made object to reach space.
The concentration camp established on Polish territory was the administrative center of a huge camp complex.
The palace of the Frankish Emperor, Charlemagne, was not only the center of the Empire, but also a center of culture
Uranus is the 7th planet from the Sun, a gas giant.
Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).
Formic acid is the simplest carboxylic acid.
Static warfare was one of the characteristics of WWI
The building material of the cell walls and fibers of plants.
Hero of Alexandria is the inventor of the first steam engine, although he regarded it as an entertaining toy.
The Apache attack helicopter, named after an American Indian tribe, was developed for the United States Army.
The main protagonists of World War II were tanks.
A white, water-soluble, sweet compound known as sugar.
The suspension bridge that stretches above the strait between San Francisco Bay and the Pacific Ocean was opened in 1937.
The Olympic Games, held in the town every 4th year after 776 B.C. made it one of the centers of ancient Greece.
Limestone is a widely and diversely used material.
Ziggurats were typical terraced step pyramids used as temples in ancient Mesopotamia.
During the substitution reaction the hydrogen atoms of methane are substituted with chlorine atoms, the by-product is hydrogen chloride.
Fatty acid molecules consist of a polar head and a non-polar tail, therefore they are suitable for removing fat stains.
One of the oxoacids of nitrogen. A colorless compound with a pungent odor, a strong oxidant.
Hydrogen atoms within hydrogen molecules are held together by a covalent bond.