Heat energy(Unit 1 & 2)

Heat

It is a invisible energy which causes sensation of hotness or coldness.

General effects of heat are:

1. Brings change in temperature

2. Brings change in demension

3. Brings change in state

4. Brings chemical changes in matter

1 joule(J)=_____ergs

10 to the power 7

1 cal=_____J

Temperature

Degree of hotness or coldness

Thermometer

Device for measuring temperature of different objects

First thermometer created by and when

Galileo in 1593 AD

Standard point or fixed point

Fixed temperature marked on the stem of a thermometer

Lower and upper standard point of thermometer

Mercury melting and boiling point

-39 degree celsius and 357 degree celsius

Melting and boiling point of alcohol is

Less than -100 degree celsius and 78 degree celcius

Degree C =K(+273 or -273)

-273

Temperature in F and C where the numerical value is same

-40 degrees