Match List - I with List - II:

	List - I Species		List - II Geometry/Shape
A.	$\mathrm{H_3O^+}$	I.	Tetrahedral
B.	Acetylide anion	II.	Linear
C.	$\mathrm{NH_4^+}$	III.	Pyramidal
D.	$\mathrm{ClO_2^-}$	IV.	Bent

Choose the correct answer from the options given below:

<p>Let&#39;s consider each species in List I and determine their geometries/shapes.</p> <p>A. $\mathrm{H_3O^+}$: This ion is formed by the addition of a proton to a water molecule. The central atom (O) is surrounded by three Hydrogen atoms and one lone pair, making its shape pyramidal.</p> <p>B. Acetylide anion: The acetylide ion ($\mathrm{C_2H^-}$ or $\mathrm{C_2^{2-}}$) has a linear geometry as the three atoms are in a straight line.</p> <p>C. $\mathrm{NH_4^+}$: The ammonium ion has a central nitrogen atom surrounded by four hydrogen atoms, giving it a tetrahedral geometry.</p> <p>D. $\mathrm{ClO_2^-}$: The chlorite ion has a central chlorine atom surrounded by two oxygen atoms and one lone pair, which gives it a bent or V-shaped geometry.</p> <p>Matching these to List II, we get:</p> <p>A. $\mathrm{H_3O^+}$ - III. Pyramidal<br/><br/> B. Acetylide anion - II. Linear<br/><br/> C. $\mathrm{NH_4^+}$ - I. Tetrahedral<br/><br/> D. $\mathrm{ClO_2^-}$ - IV. Bent</p>