Which substance does not produce a gas at both electrodes during electrolysis?

Iwll give extra points to who gets this for ! what type of reaction is this? ?

Name the element in group 17, period 2. (periodic table)

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?