Q31 of 69 Page 65

How many electrons in an atom may have the following quantum numbers?

(a) n = 4, ms= – 1/2


(b) n = 3, l = 0

(a) Total number of electrons in an atom can be found out by the following relationship

ne = 2n2


Total no of electrons when n=4, then n = 2× 42 = 32 & half of them have ms = -1/2


(b) When n = 3, L=0 means 3s orbital which can have 2 electrons.


More from this chapter

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29

Using s, p, d notations, describes the orbital with the following quantum numbers.

(a) n=1, l=0; (b) n = 3; l=1 (c) n = 4; l =2; (d) n=4; l=3.

 30

Explain, giving reasons, which of the following sets of quantum numbers are not possible.

(a) n = 0, l = 0, ml= 0, ms= + 1/2


(b) n = 1, l = 0, ml= 0, ms= – 1/2


(c) n = 1, l = 1, ml= 0, ms= + 1/2


(d) n = 2, l = 1, ml= 0, ms= – 1/2


(e) n = 3, l = 3, ml= –3, ms= + 1/2


(f) n = 3, l = 1, ml= 0, ms= + 1/2

 32

Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit.

 33

What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum?