251.

The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?

• Li²⁺ (n = 2)

• Li²⁺ (n = 3)

• Be³⁺ (n = 2)

• He⁺ ( n = 2)

Which of the following set of quantum numbers represents the highest energy of an atom?

• n =3, l=2, m=1, s= +1/2

• n=4, l=0, m=0, s= -1/2

• n=3, l=0, m=4, s= +1/2

• n=3, l=1, m=1, s=+1/2

The number of radial nodes present in 3p orbital is

• 0

• 1

• 2

• 3

The radiation with maximum frequency is

• X-ray

• radio waves

• UV rays

• IR rays

The element with the electronic configuration 1s² 2s²2p⁶3s²3p⁶3d¹⁰4s¹ is

• Cu

• Ca

• Cr

• Co

Which of the following electron has minimum energy?

• n = 4; l = 0; m= 0; s = +$\frac{1}{2}$

• n= 4; l= 1; m = ±1; s = +$\frac{1}{2}$

• n = 5; l = 0; m = 0; s = +$\frac{1}{2}$

• n = 3; l = 2; m = -2; s = +$\frac{1}{2}$

How many emission spectral lines are possible when hydrogen atom is excited to nth energy level?

• $\frac{\mathrm{n}(\mathrm{n}+1)}{2}$

• $\frac{(\mathrm{n}+1)}{2}$

• $\frac{(\mathrm{n}-1)\mathrm{n}}{2}$

• $\frac{{\mathrm{n}}^2}{4}$

Which of the following corresponds to the energy of the possible excited state of hydrogen?

• -13.6 eV

• 13.6 eV

• -3.4 eV

• 3.4 eV

The quantum number of four electrons are given below:

I. n = 4	l = 2	ml = -2	ms = -$\frac{1}{2}$
II. n = 3	l = 2	ml = 1	ms = +$\frac{1}{2}$
III. n = 4	l = 1	ml = 0	ms = +$\frac{1}{2}$
IV. n = 3	l = 1	ml = 1	ms = -$\frac{1}{2}$

The correct order of these increasing energies will be:

• IV > III > II > I

• I > II > III > IV

• I > III > II > IV

• IV > II > III > I

The correct order of the spin only magnetic moment of metal ions in the following low spin complexes, [V(CN)₆]^4-, [Fe(CN)₆]^4-, [Ru(NH₃)₆]³⁺ and [Cr(NH₃)₆]²⁺ is

• V²⁺  > Cr²⁺ > Ru³⁺ > Fe²⁺

• V²⁺ > Ru³⁺ > Cr²⁺ > Fe²⁺

• Cr²⁺ > V²⁺ > Ru³⁺ > Fe²⁺

• Cr²⁺ > Ru³⁺ > Fe²⁺ > V²⁺