Succinic acid is often found in high levels in tumors or biofluids surrounding tumors. It is a weak acid with a pKa of is 4.21. What is the reaction of succinic acid (C6H4O4) with water

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

The answer for #3 is c but i don't know why

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?