Please help!! A balloon contains 7 L of He. The pressure is reduced to 2 atm and the
balloon expands to occupy a volume of 25 L. What was the initial pressure
exerted on the balloon? (round to the nearest whole number)

How many grams of aluminum will there be in 98g of al2o3?

List the path of the respiratory system

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 ?