What is the maximum number of electrons in the second principal energy level?

What was bohr’s contribution to the planetary model

In which block of the periodic table is uranium (u) found? s blockd blockp blockf block

Which statement best summarizes the importance of ernest rutherford’s gold foil experiment? it proved that all of john dalton’s postulates were true. it verified j. j. thomson’s work on the atomic structure. it showed that an electron circles a nucleus in a fixed-energy orbit. it showed that a nucleus occupies a small part of the whole atom.