Question

1using the phrase vapor pressure and atmospheric pressure define boiling point

2does the boiling point of a liquid increase or decrease in a vacuum and why?

3 does the boiling point of a liquid increase or decrease when it is raining outside and why

can someone please help me to answer these

Answer 1

As you have been asking for 3 questions, so I `am` poosting the` `answers.

q.1 every liquid (and solid for that matter) has a vapor pressure.
at the boiling point, the vapor pressure = atmospheric pressure
at temperatures below the boiling point, the vapor pressure is dependent upon the temperature. the molecules in the liquid have energy to escape the surfrace of the liquid and become a gas molecule. as the temperature closes in on the boiling point, more molecules will have the energy to escape the surface of the liquid.

Q.2.

Pressure increases - BP increases.

Therefore, if a liquid is heated while under vacuum, the boiling point of the liquid will be decreased which will also reduce the amount of heat energy needed to boil the liquid.

Q.3.

Changes in air pressure do, indeed, affect the temperature at which water boils. The
boiling temperature falls as air pressure decreases (and as elevation increases).
Water, even cold water, evaporates at all temperature and air pressure values, and air
pressure is not a factor in providing moisture in rain. Air pressure is not low
during the formative stage of a rain, and water vapor, from the evaporation of sea
water, is fueling the developing storm even then.