3. The island of Rum in Scotland had wolves and trees 500 years ago. It now has neither. a. Offer one hypothesis for the current condition based on the concepts of keystone species and
trophic cascades. b. Suggest one way to test the hypothesis.

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

The closer the atoms are to becoming ionic the more highly dense the negatively charged side gets.