Which type of precipitation can be considered acid rain?

Gymnast always perform on padded mats. how does the mats protect the gymnast

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?

What would be the original temperature of a gas that has a volume of 2.0 l and a pressure of 2.0 atm and an unknown temperature that the volume increased to 3.5 l in its pressure decreased to 1.0 atm if the final temperature is measured to be 11°c