The energy of an electron in the ground state (n = 1) of the \mathrm{He^+} ion is -x J. Then that of an electron in the n = 2 state of the \mathrm{Be^{3+}} ion, in J, is:

D. En = -\frac{Z^2}{n^2} \times 13.6 eV. For \mathrm{He^+} (Z=2, n=1): factor 4. For \mathrm{Be^{3+}} (Z=4, n=2): factor \frac{16}{4} = 4. Same factor, so the energy is -x J.

ChemistryNEET 2024Bohr model and hydrogen spectrum

Structure of Atom

The energy of an electron in the ground state ( $n = 1$ ) of the $H e^{+}$ ion is $- x$ J. Then that of an electron in the $n = 2$ state of the $B e^{3 +}$ ion, in J, is:

A. $- \frac{x}{9}$
B. $- 4 x$
C. $- \frac{4 x}{9}$
D. $- x$ ✓

Solution

$E_{n} = - \frac{Z ^{2}}{n ^{2}} \times 13.6$ eV. For $H e^{+}$ ( $Z = 2$ , $n = 1$ ): factor $4$ . For $B e^{3 +}$ ( $Z = 4$ , $n = 2$ ): factor $\frac{16}{4} = 4$ . Same factor, so the energy is $- x$ J.

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Structure of Atom

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