An exercise about the groups and structure of organic nitrogen compounds.
A colourless liquid, easily solved by organic solvents but not by water.
One of the halogens, it may cause skin irritation.
The monomer of PVC.
A compound ion generated when a proton is added to an ammonia molecule.
The simplest aldehyde.
A biologically and practically important organic compound.
Farming consists of special agricultural activities.
Leonardo also designed a wide variety of artillery weapons.
Hungarian engineer János Csonka built his first automobiles for the Hungarian Postal Service.
The Athenian democracy was built on the community of citizens with full rights.
Narrow streets and colourful houses gave medieval towns a special atmosphere.
Buses play an important role in public transport.
Clothing reflects the lifestyle and culture of the given era and region.
Dresses reflect the lifestyles and culture of the given era and region.
Examining solids formed by the intersection of a cube and a plane.
The leader of the Ottoman Empire was the Sultan, the lord of life and death.
The infantry of the Habsburg Empire were deployed in numerous battles.
The Early Christian Necropolis in Pécs, Hungary is an outstanding historical site.
Clothing reflects the lifestyle and culture of the region's inhabitants.