Science

Important points to remember : Our solar system is a tiny part of a galaxy called  the Milky Way, which is many, many times larger…

Important points to remember : Magnets are made from alloys of iron, cobalt and nickel.  Nipermag, an alloy of iron,  nickel,  aluminium  and titanium  is…

Important points to remember : Sound  is generated by the rhythmic vibration of an object.  We can hear the sound as long as the object…

Important points to remember : Eclipses often occur in the solar system. As  seen from the earth, when a planet or a star passes behind …

Important points to remember : Metals are obtained  from their ore by extraction and purification. Impurities of  sand and  soil in an  ore are called …

Important points to remember : In the period prior to 500 BC, in countries such as  China, Greece, Rome, toothpaste  was made  by mixing  the…

Important points to remember : Many kinds of matter  found in nature are in pure form, that is, they contain only one constituent. In scientific…

Important points to remember :  Changes like  the  ripening of a fruit, spoiling of milk occur naturally. These are called  natural changes.  Many changes such…

Important points to remember : There  are more than 600 muscles  in the human body. Muscles contribute almost 40% of the weight of a healthy …

Important points to remember : cell  is the fundamental  structural  and functional  unit of living  organisms. In 1665, a scientist,  Robert  Hooke observed a thin…

Important points to remember : We have studied two types of disasters, namely, manmade and  natural disasters.  Natural disasters such as famine, lightning strikes, cloudbursts,…

Important points to remember : The moisture  in the air cools down  due to the ice cubes in the glass  and collects on the outside…

Important points to remember : Electric charge is stored even in our own bodies. All substances are made of very tiny particles. Electric charge is …

Important points to remember : Quantities such as mass, weight, distance, speed, temperature, volume are called physical quantities.  An international  system of units based on…

Important points to remember : The  minimum  distance  traversed  in a particular direction along  a straight line is  called displacement.  The length of the route…

Important points to remember : The universe includes innumerable galaxies, the space between them and also energy.  The scientist Edwin Hubble showed that there exist…

Important points to remember : The material to which objects made from iron, nickel, cobalt, etc. get attracted is called a ‘magnet’. This property of…

Important points to remember : A substance that emits light is a source of light. The natural sources of light are the sun, the stars,…

Important points to remember : Vibrations are required for the production of sound.  A medium is required for the propagation of sound.  Sound is propagated…