How does the quantum theory of atoms explain the nature of the emission-line spectrum of hydrogen

Define dew point. i am writing this part to be able to ask the question

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

Acontrol during an experiment. might change remains constant does not exist does change