I need help with number 19

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?

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

Who discovered a pattern to the elements in 1869?