The atomic number of the element from the following with lowest $1^{\text {st }}$ ionisation enthalpy is :

Given below are two statements :
Statement (I): The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.
...

The correct statements from the following are.
(A) $\mathrm{Tl}^{3+}$ is a powerful oxidising agent
(B) $\mathrm{Al}^{3+}$ does not get reduced easily
(C)...

Match the LIST-I with LIST-II

Choose the correct answer from the options given below:

The correct orders among the following are
Atomic radius: $\mathrm{B}<\mathrm{Al}<\mathrm{Ga}<\ln <\mathrm{Tl}$ Electronegativity: $\mathrm{Al}<\mathrm{Ga}<\mathrm{In}<\mathrm{Tl}<\mathrm{B}$ Density: $\mathrm{Tl}<\mathrm{In}<\mathrm{Ga}<\mathrm{Al}<\mathrm{B}$ 1st Ionisation Energy: In $<\mathrm{Al}<\mathrm{Ga}<\mathrm{Tl}<\mathrm{B}$
Choose the correct answer from...

Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is : (Given v = frequency of X-ray emitted; Z...

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: The energy required to...

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : The first...

For electron gain enthalpies of the elements denoted as $\Delta_{\mathrm{eq}} \mathrm{H}$, the incorrect option is:

Which one of the following sets of ions represents a collection of isoelectronic species? (Given : Atomic Number : $...