Chemistry · Structure of Atom

JEE Main 2025 — 29 January, Evening Shift — Question 1

For hydrogen-like species, which graph correctly represents $E$ vs $Z$ for constant $n$ ?

(Given: $E$ = energy of stationary state, $Z$ = atomic number)

Answer: B

Energy of hydrogen-like atom, given as

E_n = -13.6 \frac{Z^2}{n^2}

For constant $n$ , we have

E \propto -Z^2

Energy is always negative and varies quadratically with $Z$ .

Hence, the curve is a downward parabola.

The correct graph is given in option B.

Answer key and solution verified before publishing.

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