Which of the following statements are correct? A. The process of adding an electron to a neutral gaseous atom is always exothermic. B. The process of removing an electron from an isolated gaseous atom is always endothermic. C. The $1^{\text{st }}$ ionization energy of boron is less than that of beryllium. D. The electronegativity of C is 2.5 in ${\mathrm{CH}}_4$ and ${\mathrm{CCl}}_4$ E. Li is the most electropositive among elements of group I. Choose the correct answer from the options given below:

Choose the incorrect trend in the atomic radii (r) of the elements.

The incorrect relationship in the following pairs in relation to ionisation enthalpies is :

The elements of Group 13 with highest and lowest first ionisation enthalpies are respectively :

The correct orders among the following are Atomic radius : $\mathrm{B}Electronegativity:$\mathrm{Al} Density : $\mathrm{Tl}1stIonisationEnergy:$\mathrm{In} Choose the correct answer from the options given below:

$$\text{ Match the LIST-I with LIST-II }$$ .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-c3ow{border-color:inherit;text-align:center;vertical-align:top} LIST-I (Family) LIST-II (Symbol of Element) A. Pnictogen (group 15) I Ts B Chalcogen II Og C Halogen III Lv D Noble gas IV Mc Choose the correct answer from the options given below:

Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction?

Given below are two statements : Statement I : ${\mathrm{CH}}_3-\mathrm{O}-{\mathrm{CH}}_2-\mathrm{Cl}$ will undergo ${\mathrm{S}}_{\mathrm{N}}1$ reaction though it is a primary halide. Statement II : will not undergo ${\mathrm{S}}_{\mathrm{N}}2$ reaction very easily though it is a primary halide. In the light of the above statements, choose the most appropriate answer from the options given below :

The maximum number of RBr producing 2-methylbutane by above sequence of reactions is __________ . (Consider the structural isomers only)

The major product of the following reaction is:

Propane molecule on chlorination under photochemical condition gives two di-chloro products, " $x$ " and " $y$ ". Amongst " $x$ " and " $y$ ", " $x$ " is an optically active molecule. How many tri-chloro products (consider only structural isomers) will be obtained from " x " when it is further treated with chlorine under the photochemical condition?

Identify the products [A] and [B], respectively in the following reaction:

The ascending order of relative rate of solvolysis of following compounds is :

Given below are two statements: Statement I: The conversion proceeds well in the less polar medium. $${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{Cl}\stackrel{{\mathrm{HO}}^{-}}{\to }{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{OH}+{\mathrm{Cl}}^{(-)}$$ Statement II: The conversion proceeds well in the more polar medium. In the light of the above statements, choose the correct answer from the options given below

Following are the four molecules "P", "Q", "R" and "S". Which one among the four molecules will react with $\mathrm{H}-{\mathrm{Br}}_{(\mathrm{aq})}$ at the fastest rate?

The structure of the major product formed in the following reaction is :

The products A and B in the following reactions, respectively are $\mathrm{A}\stackrel{\mathrm{Ag}-{\mathrm{NO}}_2}{⟷}{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{Br}\stackrel{\mathrm{AgCN}}{\to }\mathrm{B}$

'P' is

Choose the correct set of reagents for the following conversion.

Which one of the following reactions will not lead to the desired ether formation in major proportion? (iso- $\mathrm{Bu}\Rightarrow$ isobutyl, sec $-\mathrm{Bu}\Rightarrow$ sec-butyl, $\mathrm{nPr}\Rightarrow \mathrm{n}$-propyl, $${}^{\mathrm{t}}\mathrm{Bu}\Rightarrow \text{ tert-butyl, }\mathrm{Et}\Rightarrow \text{ ethyl) }$$