What Is The Barrier Of Sound? The name “sound barrier” is actually a wrong way to describe a condition that exists when planes travel at a particular speed. When the speed of sound is attained, a kind of barrier is expected,...
What Is The Speed Of Sound? We make a sound every day, and with every sound, there is something that vibrated somewhere. Something moves back and forth rapidly. The sound starts with the vibration of an object. Sound has to travel...
How is a Mirage Caused? Assume a man moving about in the desert and feeling thirsty. He looks off at a distance and sees a lake of clear water, surrounded by trees. He moves on and stumbles to find only hot...
What Are X-Rays? Wilhelm Roentgen, a German scientist discovered in the year 1875, X-rays. These rays are also called Roentgen rays. Similar to light rays these are penetrating rays. They differ from light rays in the length of their waves and...
What Is Meant By Radioactivity? In the present time, everybody in the world has heard about radio-activity. There may hardly be an exception. The testing of atom bombs creates radioactivity. This is one of the great problems faced by mankind now....
What Radium Is? Radium is a radioactive element. The elements are made up of atoms. In general, atoms are stable, meaning that they do not change from year to year. A few heaviest atoms break down and change into other kinds....
What Do You Know About Atomic Energy? Atom is the source of atomic energy. Every atom has particles of energy. Parts of an atom are held together by energy. For atomic energy source of energy is the core of an atom....
What Is The Size Of One Atom? Whatever we know about atoms may not hold good tomorrow. Scientists are constantly exploring and learning new things about the atom. We have the atom-smashing machines too. The word atom has Greek origin, meaning...
What Do You Understand By Smog? In London city above 4,000 people died t between December 4th and 9th in the year 1952. The death was caused due to exposure to smog, which is so dangerous. In industrial cities, there are...
What Smoke Is? The incomplete combustion of fuels results in smoke. There would be no smoke if our fuels burn completely. The fuels In general consist of hydrogen, carbon, oxygen, nitrogen, a little sulfur, and possibly some mineral ash. In case...