A flask contains a mixture of nitrogen and oxygen gases at STP. If the partial pressure of the nitrogen is 650.0 mmHg, then what is the partial pressure of the oxygen in mmHg?

Evaporation: this is when warmth from the sun causes water from oceans, lakes, streams, ice and soils to rise into the air and turn into water vapour (gas). water vapour droplets join together to make clouds! condensation: this is when water vapour in the air cools down and turns back into liquid water.