The softness of a metal is its ability to undergo permanent deformation under applied stress. All metals have specific crystalline structures. Each structure has its own densely packed crystalline planes. There exist line defects and plane defects in a crystal system. Such defects are more in densely packed crystal systems, i.e., metallic crystals with higher density, and result in a …

While krypton is generally an inert element, in extreme volatile conditions, it can form compounds in very small quantities. There are several ways that krypton can form its fluoride: by passing through an electrical arc, proton bombardment or photochemical process. All these processes require a very heavy amount of energy. Krypton has achieved a unique importance in science. In 1960, …

Plant cells have cell organelles known as plastids, which are colouring agents. There are three types of plastids – chloroplasts (contain green pigment chlorophyll), leucoplasts (white or colourless plastids) and chromoplasts (contain other pigments). All cells have varying proportions of these. Flowers have a majority of the third type and get their colours from these. From Wikipedia Chromoplasts are plastids …

Guerrillas is derived from the Spanish language which means “little war”, guerrillas are fighters who are not regular soldiers. Working in small groups, guerrillas make sudden raids on invading forces.

A man jumping on the surface of the moon would leap six times as high as he could on earth because the moos has only one-sixth the gravity of earth: therefore the man would jump a height of 30 feet.

MAs you sip a hot liquid, air comes into your mouth along with it and cools the drink. Your saliva mixes in and cools it further. But hot stuff on your skin is just plain hot!

A few thousand million years from now, the Sun will run out of hydrogen at its center. Then the nuclear reactions will spread outwards into the region surrounding the Sun’s core. With more hydrogen to burn, the Sun will produce more energy, and it will swell up into a red giant star. As the Sun gets bigger and brighter, the …

Everything that is born must die. Not only living beings, but inanimate objects like stars too. The birth of a star The universe has massive clouds of hydrogen floating around. Sometimes, these clouds come together and form very dense and huge balls of hydrogen gas. As the clouds come close, their temperature increases. This is called a proto-star (original star). …

In November 1922 an English archaeologist, Howard Carter, found in Egypt the tomb of a pharaoh that was filled with wonderful, exciting treasure. Newspapers were full of stories of golden thrones, beds and chariots, of jeweled caskets, even of flowers still preserved in the dry, airless tomb. Carter, who was working for Lord Carnarvon, had been busy in the royal …

The first world map was chiseled on a clay tablet in ancient Babylon in 6 BC. The Greeks in 4 BC had similar maps though they correctly believed that the earth was not flat, but a sphere. The first reasonably accurate world map was drawn by hand on paper by Gerardus Mercator, a Flemish geographer. His first world map was …