According to becquerel, what created the image on photographic film when it was placed in a drawer with uranium salt crystals?
the crystals emitted something that affected the film the same way light did.
the film caused a chemical change in the crystals.
the film exposed spontaneously, even when it was not exposed to light.
the uranium spontaneously emitted radioactive particles that exposed the film.

clouds form

solid ice forms on leaves.

water droplets form on grass.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.