How many days does it take to go from a waxing gibbous to a waning

Which statement describes james chadwick’s discovery.

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 ?

The identities of substances are the same before and after which type of change