The number of d -electrons in Fe²⁺ (atomic number  Z = 26)  is different from the number of:
1. s-electrons in Mg (Z = 12)
2. p-electrons in Cl (Z = 17)
3. d-electrons in Fe (Z = 26)
4. p-electrons in Ne (Z = 10)

The angular momentum of electrons in d orbital is equal to:
1. $\sqrt{6}$ $\sout{h}$
2. $\sqrt{2}$$\sout{h}$
3. $2\sqrt{3}$ $\sout{h}$
4. 0 $\sout{h}$

What is the maximum number of orbitals that can be identified with the following quantum numbers?
n = 3, l = 1, m = 0

Calculate the energy corresponding to light of wavelength 45 nm:
(Planck's constant h = 6.63 × 10^–34 Js:
speed of light c = 3 × 10⁸ ms^–1)
1. 6.67 x 10¹⁵ J
2. 6.67 x 10¹¹ J
3. 4.42 x 10^-15 J
4. 4.42 x 10^-18 J

Based on equation E = –2.178 × 10^–18J, $\frac{{\mathrm{Z}}^2}{{\mathrm{n}}^2}$ certain conclusions are written. Which of them is not correct?

Maximum number of electrons in a subshell with l = 3 and n = 4 is:

1. 14

2. 16

3. 10

4. 12

The correct set of four quantum numbers for the valence electron of a rubidium atom (Z =37) is: