Question

if n is equal to 3 l is equal to 0 and m is equal to zero then atomic number is......
(A) 12 or 13
(B) 13 or 14
(c) 10 or 11
(D) 11 or 12

Answer with explanation​

Answer 1

Answer:

11 or 12

Explanation:

given n=3

l=0

m=0

then configuration is 3s

then atomic mumber is 11 or 12

since 11 and 12 are elements with cofiguration 3s1 amd 3s2

Answer 2

$\textbf{ \underline{ \underline{ \: Answer :– \: }}}$

$\text{\small{(D) 11 or 12}}$

$\underline{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:\: }$

$\text{ \small{n = 3, represents that\:electron is in the third shell.}}$

$\text{ \small{l = 0,</p><p></p><p> represents that the electron is in the 3s-subshell }}$

→For $\text{s} _1$ l=0.

$\text{ \small{m = 0 represents that the electrons is in the 3s - subshell}}$

[It may be 3s¹ or 3s²]

$\text{ \small{Hence, its complete electronic configuration is</p><p>}}$

$\boxed{ { \text{ \small{1s}}}^{2} ,{ \text{ \small{2s}}}^{2} ,{ \text{ \small{2p}}}^{6} ,{ \text{ \small{3s}}}^{1 \: \text{or} \: 2}}$

→$\textbf{The atomic number will be 11 or 12}$

Atom, whose atomic number 11 is Sodium [Na]

Electronic configuration → ${ \text{ \small{1s}}}^{2} ,{ \text{ \small{2s}}}^{2} ,{ \text{ \small{2p}}}^{6} ,{ \text{ \small{3s}}}^{1}}$

Atom, whose atomic number 12 is Magnesium [Mg]

Electronic configuration → $\text{ \small{1s}}}^{2} ,{ \text{ \small{2s}}}^{2} ,{ \text{ \small{2p}}}^{6} ,{ \text{ \small{3s}}}^{2}}$