When you buy a helium-filled balloon, the seller has to inflate
it from a large metal cylinder of the compressed gas. The helium
inside the cylinder has energy, as can be demonstrated for example
by releasing a little of it into the air: you hear a hissing sound,
and that sound energy must have come from somewhere. The total
amount of energy in the cylinder is very large, and if the valve is
inadvertently damaged or broken off, the cylinder can behave like a
bomb or a rocket.
Suppose the company that puts the gas in the cylinders prepares
cylinder A with half the normal amount of pure helium, and cylinder
B with the normal amount. Cylinder B has twice as much energy,
and yet the temperatures of both cylinders are the same. Explain, at
the atomic level, what form of energy is involved, and why cylinder
B has twice as much.
- Anonymous1 month ago
The energy can be represented by either half of the equation
pV = nRT
In cylinder B you have doubled "n", and so you have doubled the energy (R, T constant).