The atomic numbers of elements X, Y and Z are 19,21 and 25 respectively. The number of electrons present in the M shells of these elements follow the order.

Question

The atomic numbers of elements X, Y and Z are 19,21 and 25 respectively. The number of electrons present in the M shells of these elements follow the order. (A) Z>X>Y (B) X>Y>Z (C) Z>Y>X (D) Y>Z>X

Tardigrade Admin · Accepted Answer

19 X arrow 1 s2 2 s2 2 p6 underline3 s2 3 p6 4 s1 21 Y arrow 1 s2 2 s2 2 p6 3 s2 3 p6 4 s2 underline3 d1 25 Z arrow 1 s2 2 s2 2 p6 3 s2 3 p6 4 s2 underline3 d5 Z>Y>X

Q. The atomic numbers of elements $X, Y$ and $Z$ are 19,21 and 25 respectively. The number of electrons present in the M shells of these elements follow the order.

$Z > X > Y$

$X > Y > Z$

$Z > Y > X$

$Y > Z > X$

$_{19} X \to 1 s^{2} 2 s^{2} 2 p^{6} \underline{3 s^{2} 3 p^{6}} 4 s^{1}$

$_{21} Y \to 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} \underline{3 d^{1}}$

$_{25} Z \to 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} \underline{3 d^{5}}$

$Z > Y > X$

Q. The atomic numbers of elements X,Y and Z are 19,21 and 25 respectively. The number of electrons present in the M shells of these elements follow the order.

Z>X>Y

X>Y>Z

Z>Y>X

Y>Z>X