Question

Question: Give the electron configuration and the number of unpaired

electrons for:$\left(a\right)\mathbf{}{\mathbf{Cr}}^{\mathbf{+}\mathbf{3}}\mathbf{}\left(b\right)\mathbf{}{\mathbf{Ti}}^{\mathbf{+}\mathbf{4}}\mathbf{}\left(c\right)\mathbf{}{\mathbf{Co}}^{\mathbf{+}\mathbf{3}}\mathbf{}\left(d\right)\mathbf{}{\mathbf{Ta}}^{\mathbf{+}\mathbf{2}}$

Short answer

1. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^1$with $1$unpaired electron.
2. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$with $0$unpaired electrons.
3. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{1}3{\mathrm{d}}^5$with $6$unpaired electrons.
4. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}5{\mathrm{s}}^{2}4{\mathrm{d}}^{10}5{\mathrm{p}}^{6}6{\mathrm{s}}^{2}4{\mathrm{f}}^{14}5{\mathrm{d}}^1$with $1$ unpaired electron.

Step-by-step solution

 Step 1: Electron Configuration and Unpaired electrons.

• The distribution of electrons in atomic or molecular orbitals of an atom, molecule, or other physical structure is known as electron configuration.
• An unpaired electron could be a single electron that occupies an atom's orbital instead of as a part of a pair. Each of an atom's atomic orbitals (defined by the three quantum numbers n, l, and m) can hold two electrons (electron pair) with opposite spins.

Electron Configuration and Unpaired electrons of Given Elements

(a) Based on the periodic table, Cr has the atomic number of $24$, therefore it has $24$electrons. Electronic configuration is:role="math" localid="1663413147905" $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^5$.

When it gains a charge of $+3$, it loses $3$electrons, and will have only $21$ electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^1$ with$1$unpaired electron.

(b) Based on the periodic table, Ti has the atomic number of $22$, therefore it has $22$electrons. Electronic configuration is:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^2$.

When it gains a charge of $+4$, it loses $4$electrons, and will have only $18$electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$with $0$unpaired electrons

(c) Based on the periodic table, Co has the atomic number of $27$, therefore it has $27$electrons. Electronic configuration is:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^7$.

When it gains a charge of $+3$, it loses $3$electrons, and will have $24$electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{1}3{\mathrm{d}}^5$ with $6$unpaired electrons.

(d) Based on the periodic table, Ta has the atomic number of $73$, therefore it has $73$electrons. Electronic configuration is:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}5{\mathrm{s}}^{2}4{\mathrm{d}}^{10}5{\mathrm{p}}^{6}6{\mathrm{s}}^{2}4{\mathrm{f}}^{14}5{\mathrm{d}}^3$.

When it gains a charge of $+2$, it loses $2$electrons, and will have only $71$electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}5{\mathrm{s}}^{2}4{\mathrm{d}}^{10}5{\mathrm{p}}^{6}6{\mathrm{s}}^{2}4{\mathrm{f}}^{14}5{\mathrm{d}}^1$.