Explanation

Sulfur (S) has the smallest atomic radius among the options.

Because atomic radius decreases across a period from left to right due to increasing nuclear charge, which pulls the electrons closer to the nucleus.

Francium (Fr) has the highest atomic radius in the periodic table.

Helium has the smallest atomic radius in the periodic table.

Explanation

The irrelevant step in balancing redox equations by the oxidation number method is "Split the reaction into two half reactions."

This step is part of the ion-electron method, not the oxidation number method.

It focuses on changes in oxidation states.

Explanation

Enthalpy of neutralization is the enthalpy change when 1 mole of water is formed by the reaction of an acid with an alkali under standard conditions.

It typically releases energy as heat during the neutralization process.

Explanation

The correct formula to calculate the rate of reaction is Change in concentration of substance ÷ Time taken for the change.

This formula expresses the rate as the change in concentration of a reactant or product per unit time.

It providing a measure of how quickly the reaction occurs.

Explanation

Oxidation half-reaction :

Zn - 2e = Zn^2+

Reduction half-reaction :

Cu^2+ +2e = Cu

Zn donates two electrons to form Zn^2+ ion and Cu^2+ gains two electrons to form Cu metal.

Thus, Cu^2+ is the oxidant.

Explanation

Explanation

Energy is carried by Stationary Wave. 

 Violet light has highest energy. 

Explanation

In Friedel-Crafts acylation, an acyl group is introduced into the benzene ring in the presence of AlCl₃ (aluminum chloride).

It acts as a catalyst by facilitating the formation of the acylium ion that reacts with the benzene.

Explanation

The incorrect feature of electrolytic cells is "Alternating current source is connected to electrodes."

Electrolytic cells use direct current (DC) to drive non-spontaneous reactions, not alternating current (AC).

Explanation

Reduction is the gain of electrons.

Fe³⁺ → Fe²⁺, as iron(III) ion gains an electron, and there is no oxidation occurring simultaneously.