CBSE Class 10 Science 2025: question 7

Q7 · 1 mark · MCQMetals and Non-metals

1. (A)$\mathrm{Mg}:\stackrel{\times \times }{\underset{\times \times }{\mathrm{O}}}\to \mathrm{M}{\mathrm{g}}^{2+}{\left[\stackrel{\times \times }{\underset{\times \times }{:\mathrm{O}:}}\right]}^{2-}$ (electron-dot representation with curved arrow, as printed)
2. (B)$\mathrm{Mg}\cdot \to \stackrel{\times \times }{\underset{\times \times }{\mathrm{O}}}\to \mathrm{M}{\mathrm{g}}^{+}{\left[\stackrel{\times \times }{\underset{\times \times }{\mathrm{O}}}\right]}^{-}$ (electron-dot representation, as printed)
3. (C)$\mathrm{Mg}:+\stackrel{\times \times }{\underset{\times \times }{\mathrm{O}}}\to \mathrm{M}{\mathrm{g}}^{2+}{\left[{\stackrel{\times \times }{\underset{\times \times }{\mathrm{O}}}}^{-}\right]}_2$ (electron-dot representation, as printed)
4. (D)$2\mathrm{Mg}\times \to :\ddot{\mathrm{O}}:\to {\left[\mathrm{M}{\mathrm{g}}^{2+}\right]}_2\left[{:\ddot{\mathrm{O}}:}^{2-}\right]$ (electron-dot representation, as printed)

Figure in the paper: Four electron-dot (Lewis) representations of the formation of magnesium oxide, labelled A to D, showing magnesium atoms, oxygen atoms with crosses and dots, curved arrows, and bracketed ionic products with charges. Options are to be read from the printed figure. See it in the official paper.