It's the amount of heat you need to pump into 1 gram of the substance
in order to raise its temperature 1°C.
Different substances can have some wildly different values of specific heat.
The specific heat of water, potatoes, and rocks are especially high. That means
that those substances 'hold' a lot of heat ... which is why, before electric heating
pads were invented, rubber bags with these substances were used to warm up a
cold bed or to reduce the pain in a sore muscle.
Specific Joules:
heat of: per gm-°C
Lead 0.13
Copper 0.38
Iron 0.45
Aluminum 0.9
Water 4.2
Helium 5.2
Hydrogen 14.3
Don't quite understand the idea yet ?
Here's one way I like to think of it:
Here I have a soda straw, with the bottom end closed and some water in it.
How much water would you have to add to the straw to fill it 1 inch higher ?
Not much, right ?
OK. Now, here I have a beer barrel that's maybe about half full of water.
How much water would you have to add to the barrel to fill it 1 inch higher ?
MORE than the soda straw, right ?
OK. Now, here I have an olympic swimming pool with some water in it.
How much water would you have to add to the pool to fill it 1 inch higher ?
A lot ? I agree.
How much ? I don't know.
But definitely MORE than the straw or the barrel.
This is the way I understand specific heat:
-- The AMOUNT of water is like the heat-energy in the substance.
-- The DEPTH of the water is like the temperature of the substance.
-- The more water you pour into it, the deeper it gets.
-- The more heat you pour into it, the warmer it gets.
-- But some substances are "wider" than others.
. . . . . Lead is very skinny, like the straw.
0.13 joule of heat added to a gram of it is enough to raise it 1°C.
. . . . . Water is a 'fatter' substance, like the barrel.
You have to pour 4.2 joules into a gram of it, to raise it 1°C.
. . . . . Hydrogen is incredibly fat, like the pool.
You have to pour 14.3 joules into 1 gram of it, to raise it 1°C.
==> Hydrogen needs 110 times as much heat energy added as
Lead needs, to make 1 gram of each substance 1°C warmer than
they are now.
The specific heat of Hydrogen is 110 times the specific heat of Lead !