Help me please I’ll give you brainest

i believe the answer is three water molecules

if the temperature drops and becomes cool

then the atmosphere can be freezing as the water vapor in the air is at maximum (100%) and can be severely cold

also can be snowing lightly as the moisture in the air will start to solidify

and btw this is not chemistry but

when the pressure is increased, there will be a shift to the reactants side. decreasing the volume will increase pressure. when you decrease the volume, the gaseous species get more tightly packed of the concentrations of gaseous species increase.

le chatelier's principle says that the system wants to undo this concentration increase so it can decrease pressure.

since the reactants only have 1 mol of gas (only pcl5) and the products have 2 mol of gas (both pcl3 and cl2), it shifts to reactants to decrease concentration, thereby lowering the pressure