What is used to determine the number of each atom in an ionic formula?

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 ?

Which suspect most likely committed the robbery and how do you know

How many moles of oxygen gas are produced from the decomposition of six moles of potassium