Question

State the following questions:

a) The designation of the subshell with n=5 and l=1

b) The designation of the subshell with n=5 and l=3

c)The number of unpaired electrons in a Mo atom

d)The number of unpaired electrons in an arsenic atom

e)The lowest value of n for which a f-subshell can occur

f)The maximum number of electrons possible in an atom with n=4

g)The number of electrons which can have n=1, l=1, ml= -1, ms=+1/2

h)The number of electrons which can have n=2, l=-1, ml= 1, ms=+1/2

Answer 1

l = 0 corresponds s orbitals

l = 1 corresponds p orbitals

l = 2 corresponds d orbitals

l = 3 corresponds f orbitals

a)

The designation of the subshell with n=5 and l=1 : 5p

b)

The designation of the subshell with n=5 and l=3 : 5f

c)

Electron configuration of Mo = 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d⁵5s¹

Both 4d and 5s orbital contain unpaired electrons.

Number of unpaired electrons in 4d orbital = 5

Number of unpaired electrons in 5s orbital = 1

Total number of unpaired electrons in Mo atom = (5 + 1) = 6

d)

Electron configuration of As = 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p³

Only 4p orbital contains 3 unpaired electrons.

Hence, the number of unpaired electrons in As atom = 3

e)

The lowest value of n for which a f-subshell can occur = 4

4f is the lowest energy f orbital.

f)

The maximum number of electrons possible in an atom with n=4 = 32

4s²4p⁶4d¹⁰4f¹⁴ = 32 electrons

g)

The number of electrons which can have n=1, l=1, ml= -1, ms=+1/2 = 1

Every electron has set of 4 unique quantum numbers (Pauli exclusion principle).

h)

The number of electrons which can have n=2, l=-1, ml= 1, ms=+1/2 = 0

The value of azimuthal quantum number (l) can not be negative.