【单选题】A sample of a certain element is placed in a 0.300 T magnetic field and suitably excited. How far apart are the Zeeman components of the 450 nm spectral line of this element? ( )
【简答题】A lot of students are having all kinds of sports on the sports field. A football is going on right now between Class 3 and Class 4. We don’t know which team will win. Look at those people over th...