I dont know how to do this but i think maybe you would probably subtract.....
Answer:
The amount of water vapor in a given volume of air is humidity.The amount of water vapor in the air at any one time depends on temperature . Warmer air holds more water than cooler air. Clouds form when humidity is low and thetemperature is high . Relative humidity is defined as the amount of water vapor in the air divided by the amount that would have to be present in the same air to form a cloud or condense on a surface. Dew is related to the humidity of the previous day. The air temperature at which water vapor in the air condenses onto cool surfaces is the dew point.
Explanation:
Physical. When you simply desolve something with water, to don't actually change it. This action can be undone.
An example of a chemical reaction is when the cells within completely change. You you burn wood, you can't go back in time and un-burn it. Does that make sense?
There would be 2 which would be on the oxygen
