An element with mass number $181$ contains $32\%$ more neutrons as compared to protons. What is the symbol of that element?

The relative basic strength of the compounds is correctly shown in the option.

Observe the following reaction
\(\mathrm{Cl}_2(\mathrm{~g})+2 \mathrm{OH}^{-}(\mathrm{aq}) \rightarrow \mathrm{ClO}^{-}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})+\mathrm{H}_2 \mathrm{O}(\mathrm{l})\)
Identify the correct statements about this reaction
I. \(\mathrm{Cl}_2(\mathrm{~g})\) is oxidized to \(\mathrm{ClO}^{-}\)(aq)
II. \(\mathrm{Cl}_2(\mathrm{~g})\) is oxidized to \(\mathrm{Cl}^{-}(\mathrm{aq})\)
III. \(\mathrm{Cl}_2(\mathrm{~g})\) is reduced to \(\mathrm{ClO}^{-}\)(aq)
IV. \(\mathrm{Cl}_2(\mathrm{~g})\) is reduced to \(\mathrm{Cl}^{-}(\mathrm{aq})\)
The correct answer is

In Lassaigne sodium fusion test, \(\mathrm{N}\) and \(\mathrm{S}\) of an organic compounds are converted into

The formation of oxide ion \(\mathrm{O}^{2-}\) from oxygen atom requires an exothermic reaction, followed by an endothermic step as shown below. The process of formation of \(\mathrm{O}^{2-}\) in gas phase is unfavorable \(\left(\Delta H^{\ominus}=+\right.\) ve \()\), even though it has stable configuration of the nearest noble gas neon. This is because
\(\begin{aligned} & \mathrm{O}(g)+e^{-} \longrightarrow \mathrm{O}^{-}(g) ; \Delta H^{\ominus}=-141 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \mathrm{O}^{-}(g)+e^{-} \longrightarrow \mathrm{O}^{2-}(g) ; \Delta H^{\ominus}=+760 \mathrm{~kJ} \mathrm{~mol}^{-1}\end{aligned}\)

The energy required (in eV) to excite an electron of \(\mathrm{H}\)-atom from the ground state to the third state is

'Natalite' is used as

A person of mass \(M=90 \mathrm{~kg}\) standing on a smooth horizontal plane of ice throws a body of mass \(m=10 \mathrm{~kg}\) horizontally on the same surface. If the distance between the person and body after \(10 \mathrm{~s}\) is \(10 \mathrm{~m}\), then the KE of the person (in \(\mathrm{J}\)) is

The distance between the focii of the ellipse \(x=3 \cos \theta\), \(y=4 \sin \theta\) is

Truth table for the given circuit is

If \(A+B+C=270^{\circ}\), then \(\cos 2 A+\cos 2 B+\cos 2 C\) is equal to :

A steel wire of length \(1 \mathrm{~m}\), mass \(0.1 \mathrm{~kg}\) and uniform area of cross section \(10^{-6} \mathrm{~m}^2\) is rigidly fixed at both the ends without any tension. Its temperature is lowered by \(20^{\circ} \mathrm{C}\) and transverse waves are set up by plucking the wire at the middle. The frequency of the fundamental mode is
\[
\left(\mathrm{Y}=200 \mathrm{GPa}, \alpha=1.21 \times 10^{-5}{ }^{\circ} \mathrm{C}^{-1}\right)
\]

Two bodies having kinetic energy in the ratio $4: 1$, are moving with same linear velocity. The ratio of their masses is