Define heat in terms of K.E. Give its SI unit.
The total sum of kinetic energy contained by the molecules of the body is called the heat energy of that body.
Its SI unit is Joule.
We can measure the temperature of 100°C with a mercury thermometer but not with an alcohol thermometer. Why?
We all know that the FP of alcohol is - 1150C and BP is780C. But the FP of mercury is - 350C and BP is 3570C. So, mercury has a normal physical state at 1000C and can measure temperature. But, alcohol starts boiling if the temperature raised to 780C. So, it changes to a gas state at 1000C and cannot measure temperature. Hence, we can measure the temperature of 1000C with a mercury thermometer but not with an alcohol thermometer.