Chapter 3, Problem 3.24E

Which of the following electron configurations correspond to an excited state? Identify the atoms and write the ground-state electron configuration where appropriate. a. 1s22s23p1 b. 1s22s22p6 c. 1s22s22p43s1 d. [Ar]4s23d54p1 How many unpaired electrons are present in each of these species?

Explain why Al is a member of group 13 rather than group 3?

Write electron configurations for the following elements. a. The Group III A element in the same period as 4Be b. The Period 3 element in the same group as 5B c. The lowest-atomic-numbered metal in Group IIA d. The two Period 3 elements that have no unpaired electrons

What is the difference between core electrons and valence electrons? Why do we emphasize the valence electrons in an atom when discussing atomic properties? What is the relationship between valence electrons and elements in the same group of the periodic table?

Which of the following has two unpaired electrons? (a) Mg (b) Si (c)S (d) Both Mg and S (e) Both Si and S.

For elements l36, there are two exceptions to the filling order as predicted from the periodic table. Draw the atomic orbital diagrams for the two exceptions and indicate how many unpaired electrons are present.