List 5 sources of point- source pollution

List four observations that indicate that a chemical reaction may be taking place

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?