Please choose the correct answer to the question: The noble gases, helium, neon, argon, krypton, xenon, and radon, rarely react with other elements because they

Answer1: are low-density gases. Answer2: are not abundant on Earth. Answer3: have complete outermost energy levels. Answer4: have two electrons in their outermost energy level.

Answer format: answer1/answer2/answer3/answer4