Electron Configuration Video Lessons

Concept: Understanding Periodic Law

Problem: Which of these ions have five d electrons in the outermost d subshell?a) Tc2+b) Y2+c) Ru2+d) Mn2+ e) Re2+f) Zn2+g) Fe2+Which of these ions have one d electron in the outermost d subshell?a) Sc2+b) Hg2+c) Tc2+d) Fe2+e) Cd2+f) Y2+g) Zn2+

FREE Expert Solution

neutral atom:                       atomic number = # of protons = # of electrons

a) Tc2+

Tc: atomic # 43 = 43 e-

Nearest noble gas:  Kr

Noble gas electron configuration Tc:        [Kr]5s24d5

+2 charge → lost 2 e-

**remove e from the outermost shell: 5s2

Noble gas electron configuration Tc2+:     [Kr]4d5

outermost d subshell has five electrons.

b) Y2+

Y: atomic # 39 = 39 e-

Nearest noble gas:  Kr

Noble gas electron configuration Y:        [Kr]5s24d1

+2 charge → lost 2 e-

**remove e from the outermost shell: 5s2

Noble gas electron configuration Y2+:     [Kr]4d1

outermost d subshell doesn't have five electrons.

c) Ru2+

Ru: atomic # 44 = 44 e-

Nearest noble gas:  Kr

Noble gas electron configuration Ru:        [Kr]5s24d6

+2 charge → lost 2 e-

**remove e from the outermost shell: 5s2

Noble gas electron configuration Tc2+:     [Kr]4d6

outermost d subshell doesn't have five electrons.

d) Mn2+

Mn: atomic # 25 = 25 e-

Nearest noble gas:  Ar

Noble gas electron configuration Mn:        [Ar]4s23d5

+2 charge → lost 2 e-

**remove e from the outermost shell: 4s2

Noble gas electron configuration Tc2+:     [Ar]3d5

outermost d subshell has five electrons.

e) Re2+

Re: atomic # 75 = 75 e-

Nearest noble gas:  Xe

Noble gas electron configuration Re:        [Xe]6s24f145d5

+2 charge → lost 2 e-

**remove e from the outermost shell: 6s2

Noble gas electron configuration Tc2+:     [Ar]4f143d5

outermost d subshell has five electrons.

f) Zn2+

Zn: atomic # 30 = 30 e-

Nearest noble gas: Ar

Noble gas electron configuration Zn:        [Ar]4s23d10

+2 charge → lost 2 e-

**remove e from the outermost shell: 4s2

Noble gas electron configuration Tc2+:     [Ar]3d10

outermost d subshell doesn't have five electrons.

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Problem Details

Which of these ions have five d electrons in the outermost d subshell?

a) Tc2+

b) Y2+

c) Ru2+

d) Mn2+

e) Re2+

f) Zn2+

g) Fe2+

Which of these ions have one d electron in the outermost d subshell?

a) Sc2+

b) Hg2+

c) Tc2+

d) Fe2+

e) Cd2+

f) Y2+

g) Zn2+