Element $M$ forms an ion, $M^{2+}$ and element $X$ forms an ion, $X^{2-}$. The electronic arrangemen

Question

Element $M$ forms an ion, $M^{2+}$ and element $X$ forms an ion, $X^{2-}$. The electronic arrangements of these ions are shown as \Which of the following statements about the elements $M$ and $X$ is/are incorrect?\ I. $M$ is in group 2 and period 4 of the periodic table.\ II. $M$ is a non-metal and $X$ is a metal.\ III. $X$ is in group 15 and period 2 of the periodic table.\ IV. $M$ and $X$ form $M X$ type compound.\ V. On moving from $M$ towards $X$ in the periodic table, electronegativity decreases.\

Professor PC Thomas Classes · Answer

(a) : From the given electronic arrangements of ions,
 $M^{2+}$ ion : $2,8,8 \quad X^{2-}$ ion : 2,8\ Thus, $M: 2,8,8,2$ and $X: 2,6$\ So, $M$ is Ca and $X$ is O .\ I. Ca is in group 2 and period 4 of the periodic table.\ II. Ca is a metal and O is non-metal.\ ∴ Statement II is incorrect.\ III. O is in group 16 and period 2 of the periodic table.\ ∴ Statement III is incorrect.\ IV. Ca and O form compound CaO .\ V. On moving from Ca towards O in the periodic table, electronegativity increases.\ $	herefore \quad$ Statement V is incorrect.