How many unpaired valence electrons are there for an element with the valence shell configuration ns2(n-1)d10np4 14 3 4 2

6.84 Which graph correctly depicts the first ionization energy of three elements in groups 14 (dashed line) and 17 (solid line)? Explain the reasoning you used to make your choice.

Answer the questions below concerning ground state electron configurations. (a) What element has the electron configuration [Ar]3d64s2? (b) What element has a 2+ ion with the configuration [Ar]3d5? Is the ion paramagnetic or diamagnetic? (c) Mow many unpaired electrons are in a Ni2+ ion? (d) The configuration for an element is given here. What is the identity of the element? Is a sample of the element paramagnetic or diamagnetic? How many unpaired electrons does a 3 ion of this element have? (e) What element has the following electron configuration? Write a complete set of quantum numbers for electrons 1-3.

Explain briefly why each of the following is not a possible set of quantum numbers for an electron in an atom. (a) n = 2, = 2, m = 0 (b) n = 3, = 0, m = -2 (c) n = 6, = 0, m = 1

Arrange the following groups of atoms in order of increasing size. a. Rb, Na, Be b. Sr, Se, Ne c. Fe, P, O

Calculate the effective nuclear charge, Z, on these electrons in a tin atom (a) 5s; (b) 5p; and (c) 4d.

Using complete subshell notation ( 1s22s22p6, and so forth), predict the electron configurations of the following ions. (a) N3- (b) Ca2+ (c) S- (d) Cs2+ (e) Cr2+ (f)Gd3+

On which quantum numbers does the energy of an electron depend in each of the following? a. a one-electron atom or ion b. an atom or ion with more than one electron

Write one possible set of quantum numbers for the valence electrons of calcium.

The following numbers are the ratios of second ionization energy to first ionization energy: Na: 9.2 Mg: 2.0 Al: 3.1 Si: 2.0 P: 1.8 S: 2.3 Cl: 1.8 Ar: 1.8 Explain these relative numbers.