Im really bad at physics lol

Which of the following are not typically included in the periodic table? a. atomic mass b. element symbol c. isotopes d. number of electrons

Although longitudinal waves can travel through all media types what is the disadvantage of this type of wave transmission? a) he efficiency of he wave transmission is greatly diminished as the media becomes less dense b) the oscillation of one set of particles has a huge impact on neighboring particles c) particles become too close together as they bump into each other making it more likely to hit other particles down the line

Which is an advantage of subdividing science into different areas?