What changes direction in a regular pattern ?

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 ?

An engineer wishes to design a container that will hold 12.0 mol of ethane at a pressure no greater than 5.00x10*2 kpa and a temperature of 52.0 degrees celsius. what is the minimum volume the container can have?

H2o is a single atom of wat true or false?