Answer all the questions (10 points) 13. Write the electronic configurations of the following ions in the ground state: a) Li+, b) H-, c)N3- , d)F-, e)S2-, f) Al3+, g) Se2-, h) Br-, i) Rb+, j) Sr2+, k) Sn2+, l) Te2, m) Ba2+, n) Pb2+, o) In3+, p) Tl+, q) Tl3+. 14. Which of the following species are isoelectronic with respect to each other? C, Cl-, Mn2+, B, Ar, Zn, Fe3+, Ge2+. 15. Define atomic radius. Does the size of an atom have a precise meaning? 16. How does atomic radius change as you move a) from left to right across a period and b) from top to bottom across a group on the periodic table? 17. Why is the n = 2 electron shell in carbon closer to the nucleus than the same shell in neon? 18. The distance between the nuclei of the fluorine atoms in the F2 molecule is 1.43. What is the atomic radius of fluorine?