What is the result of adding (2.50 × 103) and (2.5 × 102)

Describe the interaction that occurs between two objects with the same electrical charge.

Find the mass, in grams, of 5.00*10^23 molecules of f2

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