The volume of a monatomic ideal gas doubles in an isothermal expansion. by what factor does its pressure change?

The pressure of the gas changes by a factor of 2

Explanation:

An isothermal expansion is a process in which a gas expands (or contracts), keeping a constant temperature.

On the other hand, the expression for an Ideal Gas is:  

(1)

Where:  

is the pressure of the gas  

is the volume of the gas  

the number of moles of gas  

is the gas constant  

is the absolute temperature of the gas

Now, if the temperature keeps constant, we can use Boyle's law, which relates the volume and pressure of a certain amount of gas maintained at a constant temperature:

(2)

Where are the initial pressure and initial volume of the gas and are the final pressure and final volume of the gas.

If:

(3)

(4) where

Then:

(5)

(6)

(7)

Finally:

(8) This means the pressure of the gas changes by a factor of 2.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.