Arrange the following elements in increasing order of electronegativity: $\mathrm{N}$, $\mathrm{O}$, $\mathrm{F}$, $\mathrm{C}$, $\mathrm{Si}$.

Solution & Explanation

\textbf{Answer:} (D) $\text{Si}<\text{C}<\text{N}<\text{O}<\text{F}$ \textbf{Solution:} Electronegativity increases with $Z_{\text{eff}}$ and decreases with atomic size. $\mathrm{Si}$ lies in period 3 and is the least electronegative here. Across period 2, electronegativity rises in the order $\text{C}<\text{N}<\text{O}<\text{F}$. The overall increasing order is $\text{Si}<\text{C}<\text{N}<\text{O}<\text{F}$.