Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The first ionisation enthalpy decreases across a period.
Reason R: The increasing nuclear charge outweighs the shielding across the period.
In the light of the above statements, choose the most appropriate from the options given below:
Held on 29 Jan 2024 · Verified 6 Jul 2026.
Both A and R are true and R is the correct explanation of A
A is true but R is false
A is false but R is true
Both A and R are true but R is NOT the correct explanation of A
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First and second ionization enthalpies of lithium are $520$ kJ mol$^{-1}$ and $7297$ kJ mol$^{-1}$ respectively. Energy required to convert $3.5$ mg lithium (g) into $\text{Li}^{2+}$(g) $[\text{Li(g)} \rightarrow \text{Li}^{2+}\text{(g)}]$ is _______ kJ mol$^{-1}$. (nearest integer) [Molar mass of Li $= 7$ g mol$^{-1}$]
Regarding the hydrides of group 15 elements $\mathrm{EH}_{3}(\mathrm{E}=\mathrm{N}, \mathrm{P}, \mathrm{As}, \mathrm{Sb})$, select the correct statement from the following: A. The stability of hydrides decreases down the group. B. The basicity of hydrides decreases down the group. C. The reducing character increases down the group. D. The boiling point increases down the group. Choose the correct answer from the options given below:
Which of the following elements has the highest electronegativity?
Which of the following elements has the highest electronegativity?
In a period, the first ionisation enthalpy of the element at extreme left and the negative electron gain enthalpy of the extreme right element, except noble gases, are respectively.
Work through every JEE Main Inorganic Chemistry PYQ, year by year.