What is the maximum number of electrons that can be held in the level n = 3?

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

You have a liquid that exhibits diltancy. you want to pour it from a bottle. what should you do to the bottle before pouring

What type of radiation is lead emitting in the following equation? alpha particles beta particles gamma rays