% subject: chemistry
% type: mcq_mc
% has_diagram: false

\item Which of the following statements regarding the periodic table is/are correct?

\begin{tasks}(1)
    \task Ionization energy generally increases across a period \ans
    \task Electron affinity of noble gases is very high
    \task Electronegativity increases down a group
    \task Atomic radius decreases across a period \ans
\end{tasks}

\begin{solution}
\begin{align*}
\intertext{Option (a) is correct. Across a period, effective nuclear charge increases, making it harder to remove an electron. Hence ionization energy increases.}
\intertext{Option (b) is incorrect. Noble gases have completely filled orbitals and very low (near zero or negative) electron affinity.}
\intertext{Option (c) is incorrect. Electronegativity decreases down a group due to increasing atomic size and shielding effect.}
\intertext{Option (d) is correct. Across a period, increasing nuclear charge pulls electrons closer, decreasing atomic radius.}
\intertext{Therefore, the correct options are (a) and (d).}
\end{align*}
\end{solution}
