The temperature at which a real gas obeys the ideal gas laws at fairly wide range of pressure is

The potential energy of the electron in an orbit of H-atom would be

(a) –mv²              (b) –e² / r²             (c) –(1/2) mv²            (d) –e² / 2r

An electron is moving with a kinetic energy of 4.55 x 10^-25 What will be the de-Broglie wave length for this electron?

(a) 5.28 x 10^-7 m                    (b) 7.28 x 10^-7 m           

(c) 2 x 10^-10 m                                (d) 3 x 10^-5 m

The number of orbital in a sub-shell is equal to

(a) n²               (b) 2l                (c) 2l + 1              (d) m

The electronic transition from n = 2 to n = 1 will produce the shortest wavelength in

(a) H-atom           (b) D-atom              (c) He⁺ ion             (d) Be⁺³ ion

The orbital angular momentum of an electron in 2s-orbital is

(a)     (b) zero             (c)                     (d)

The difference between nth and (n+1)th Bohr’s radius of H-atom is equal to its (n-1)th Bohr’s radius. The value of n is

The wave number of first line of Balmer series of hydrogen is 152,000 cm^-1. The wavelength of first Balmer line of Li⁺² ion is

(a) 15,200 cm^-1              (b) 60,800 cm^-1             

(c) 76,000 cm^-1              (d) 1,36,800 cm^-1

A possible set of quantum numbers for the last electron added to a gallium atom (Z = 31) in its ground state is

                 n                 l                m                  s

(a)             4                1               -1              +1/2

(b)             4                0                0               -1/2

(c)             3                2               +2              +1/2

(d)             3                0                0               -1/2

Three isotopes of an element have mass numbers M, (M + 1) and (M + 2). If the mean mass number is (M + 0.5) then which of the following ratio may be accepted for M, (M + 1), (M + 2) in that order.

Find out the longest wavelength of light just able to eject a least bound photoelectron from Cu (work function = 4.3 eV) 1 eV = 1.6 x 10^-12 ergs

If an electron be accelerated through a potential difference of 100 V, then its wavelength would be [mass of electron 9.1 x 10^-28 gm]

(a) 5.9 Å              (b) 3.3 x 10^-1 Å              (c) 1.2 Å               (d) None

What is the no. of nodal plane for p_y orbital ?

For a d-electron, the orbital angular momentum is

(a)              (b)                 (c)                 (d) none of these

A 3p electron has