Q 14P - Chemistry: Molecular Nature Of Matter And Change

Question

Question: Give the electron configuration and the number of unpaired electrons for $\left(a\right)\mathbf{ }{\mathbf{Sc}}^{\mathbf{+}\mathbf{3}}\mathbf{ }\left(b\right)\mathbf{ }{\mathbf{Cu}}^{\mathbf{+}\mathbf{2}}\mathbf{ }\left(c\right)\mathbf{ }{\mathbf{Fe}}^{\mathbf{+}\mathbf{3}}\mathbf{ }\left(d\right)\mathbf{ }{\mathbf{Nb}}^{\mathbf{+}\mathbf{3}}$

Step-by-Step Solution

Answer

(a) Electron configuration and unpaired electrons of ${\mathrm{Sc}}^{+3}$$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$with 0 unpaired electrons.

(b) Electron configuration and unpaired electrons of ${\mathrm{Cu}}^{+2}$$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$with 3 unpaired electrons.

(c) Electron configuration and unpaired electrons of ${\mathrm{Fe}}^{+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.

(d) Electron configuration and unpaired electrons of ${\mathrm{Nb}}^{+3}$$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}4{\mathrm{p}}^{6}5{\mathrm{s}}^{0}4{\mathrm{d}}^2$with 2 unpaired electrons.

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

Step 2: Electron Configuration and Unpaired electrons of elements

(a) Based on the periodic table, Sc has the atomic number of $21$, therefore it has $21$ electrons. Electronic configuration of Sc is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^1$.

When it gains a charge of $+3$, it loses $3$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.

 

(b) Based on the periodic table, Cu has the atomic number of $29$, therefore it has$29$ electrons. Electronic configuration of Cu is$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{1}3{\mathrm{d}}^{10}$.

When it gains a charge of $+2$, it loses $2$ electrons, and will have only $27$electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^7$ with $3$ unpaired electrons.

 

(c) Based on the periodic table, Fe has the atomic number of $26$, therefore it has $26$ electrons. Electronic configuration of Fe is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^6$.

When it gains a charge of $+2$, it loses $2$ 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 $3$ unpaired electrons

 

(d) Based on the periodic table, Nb has the atomic number of $41$, therefore it has $41$electrons. Electronic configuration of Nb is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}4{\mathrm{p}}^{6}5{\mathrm{s}}^{2}4{\mathrm{d}}^2$.

When it gains a charge of $+3$, it loses $3$ electrons, and will have only $38$electrons with electron configuration:$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}4{\mathrm{p}}^{6}5{\mathrm{s}}^{0}4{\mathrm{d}}^2$ with $2$ unpaired electrons.