Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 2. Is Matter Around Us Pure
Pure Substances
Metals generally have high melting points and boiling points : This means that most of the metals melt and vaporise at high temperatures. Example. Iron is a metal having a high melting point of 1535ºC. This means that solid iron melts and turns into liquid iron on heating to a high temperature of 1535ºC. Metals have high densities : This means that metals are heavy substances. Example. The density of iron metal is 7.8 g/cm3 which is quite high. Metals are sonorous : This means that metals make a ringing sound when we strike them. Example. Plate type musical instruments like cymbals (manjira), and wires (or strings) for stringed musical instruments such as violin, guitar, sitar and tanpoora, etc. Metals usually have a silver or grey colour : (except copper and gold). Copper has a reddish-brown colour whereas gold has a yellow colour.