The reaction in a fuel cell is used to power cars and other devices. Is it an endothermic or exothermic reaction? Explain.

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

What must happen before a body cell can begin mitotic cell division

How is the use of hydroelectric power related to the sun