Year: 2025
Topic: Structure of Atom
Time :
1. Energy and radius of first Bohr orbit of He
+
and Li
2+
are
[Given R
H
= 2.18 × 10
-18
J, ao = 52.9 pm]
(1). \(E_n\left(Li^{2+}\right)\, =\, -8.72 \times 10^{-16}\, J\);
\(r_n\left(Li^{2+}\right)\, =\, 17.6\, pm\)
\(E_n\left(He^{+}\right)\, =\, -19.62 \times 10^{-16}\, J\);
\(r_n\left(He^{+}\right)\, =\, 17.6\, pm\)
(2). \(E_n\left(Li^{2+}\right)\, =\, -19.62 \times 10^{-18}\, J\);
\(r_n\left(Li^{2+}\right)\, =\, 17.6\, pm\)
\(E_n\left(He^{+}\right)\, =\, -8.72 \times 10^{-18}\, J\);
\(r_n\left(He^{+}\right)\, =\, 26.4\, pm\)
(3). \(E_n\left(Li^{2+}\right)\, =\, -8.72 \times 10^{-18}\, J\);
\(r_n\left(Li^{2+}\right)\, =\, 26.4\, pm\)
\(E_n\left(He^{+}\right)\, =\, -19.62 \times 10^{-18}\, J\);
\(r_n\left(He^{+}\right)\, =\, 17.6\, pm\)
(4). \(E_n\left(Li^{2+}\right)\, =\, -19.62 \times 10^{-16}\, J\);
\(r_n\left(Li^{2+}\right)\, =\, 17.6\, pm\)
\(E_n\left(He^{+}\right)\, =\, -8.72 \times 10^{-16}\, J\);
\(r_n\left(He^{+}\right)\, =\, 26.4\, pm\)