1

### IIT-JEE 1985

Bohr Model can explain
A
the spectrum of hydrogen atom only
B
spectrum of an atom or ion containing one electron only
C
the spectrum of the hydrogen molecule
D
the solar spectrum
2

### IIT-JEE 1984

Which electronic level would allow the hydrogen atom to absorb a photon but not to emit a photon?
A
3s
B
2p
C
2s
D
1s
3

### IIT-JEE 1984

Correct set of four quantum numbers for the valence (outermost) electron of rubidium (Z = 37) is
A
5, 0, 0, $+ {1 \over 2}$
B
5, 1, 0, $+ {1 \over 2}$
C
5, 1, 1, $+ {1 \over 2}$
D
6, 0, 0, $+ {1 \over 2}$
4

### IIT-JEE 1984

The increasing order (lowest first) for the values of e/m (charges/mass) for electron (e), proton (p), neutron (n) and alpha particle ($\alpha$) is:
A
e, p, n, $\alpha$
B
n, p, e, $\alpha$
C
n, p, $\alpha$, e
D
n, $\alpha$, p, e