Questions

When exposed to certain frequencies of radiation, such as radio waves, the subatomic particles called electrons that orbit an atom's nucleus will "jump" back and forth between energy states. Clocks based on this jumping within atoms can therefore provide an extremely precise way to count seconds.It is no surprise then that the international standard for the length of one second is based on atoms. Since 1967, the official definition of a second is 9,192,631,770 cycles of the radiation that gets an atom of the element called caesium to vibrate between two energy states.

The short and swift streams running down the Scandinavian mountains have been harnessed for power which also compensates for the absence of coal and oil.

Crop Rotation is the practice of growing a series of dissimilar or different types of crops in the same area in sequenced seasons. It is done so that the soil of farms is not used for only one set of nutrients. It helps in reducing soil erosion and increases soil fertility and crop yield. The British agriculturist Charles Townshend (1674–1738) popularised this revolutionary technique in the 18th century.