An example of a physical change is A) crushing a rock

B) shirt fading in the sun

(From USATESTPREP)

A: Crushing a Rock

Explanation:

The rock is physicially being broken down and turned into either smaller pieces of rock or dust if you pound it hard enough.

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.