Opening balance of capital Rs 175000 and liabilities Rs 25000

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

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

As you move from right to left on the periodic table the atomic radius fill in the blank