The use of mercury is very in a number ofdeviceslike thermometer, blood pressure measuring apparatus, mercury cell (containing HgO) used inhearing aids and watchesetc. Mercury is toxic and causes pollution if it entersthe atmosphere and if somehowit enters our body , itdoes not get eliminated easily. Therefore, thesedevies are being replaced by others which do not mercury. For example , in schools , mercury thermometer sare being replaced byother thermometers ( such as using alcohol etc. ). After reading the above paragraph , answer the following questions ? (i) What values the above paragraph , answer the following questions: (ii) Why was mercury preferred in thermometers ?

The use of mercury is very in a number ofdeviceslike thermometer, bloo

1.	The use of mercury is very in a number ofdeviceslike thermometer, blood pressure measuring apparatus, mercury cell (containing HgO) used inhearing aids and watchesetc. Mercury is toxic and causes pollution if it entersthe atmosphere and if somehowit enters our body , itdoes not get eliminated easily. Therefore, thesedevies are being replaced by others which do not mercury. For example , in schools , mercury thermometer sare being replaced byother thermometers ( such as using alcohol etc. ). After reading the above paragraph , answer the following questions ? (i) What values the above paragraph , answer the following questions: (ii) Why was mercury preferred in thermometers ?
Answer» SOLUTION :(i) The use of mercury apparatuses should be avoidedas far as POSSIBLE. Before disposing off,mercury should be recoveryand STORED properly orspent cells hsould be processedfor the recovery off mercury . (ii) Mercury was preferred in the thermometers because it is a LIQUID which does not stickto glassand hadhigh coefficientof expansion and EXPANDS at a uniform rate when heated.