Chemistry F.Sc-I Ch# 5,Multiple Choice Questions

Multiple Choice Questions (MCQs)

Q.1 The quantum number which is not derived from Schrödinger wave equation is?
A) Principal
B) Azimuthal
C) Magnetic
D) Spin
 Q.2 The total number of electrons can be accommodated in 5th shell of an atom are
A) 2
B) 18
C) 32
D) 50
 Q.3 The formula is used to calculate number of orbitals in a subshell is
A) n^2
B) 2l + 1
C) 2(2l + 1)
D) l = n - 1
 Q.4 The electronic configuration of one of the following atom does not follows Hund's rule
A) F
B) O
C) N
D) P
 Q.5 The quantum number is used to describe orientation of orbitals is
A) n
B) l
C) m
D) s
Q.6 The greater value of (n + l) is for
A) 3d
B) 4s
C) 5p
D) 4f
 Q.7 The least no.of electrons are present in the valence shell of
A) Zn
B) Cu
C) Ca
D) Cl
 Q.8 The volume of space in which there is ________ chance of finding an electron is called atomic orbital
A) 80%
B) 90%
C) 95%
D) 99%
 Q.9 The electron goes into______ subshell after filling 5p subshell
A) 4f
B) 6s
C) 4d
D) 4p
 Q.10 The shape of d-subshell is
A) Spherical
B) Dumble
C) Bilobed dumble
D) Complicated

Answers:
1)  D
2)  D
3)  B
4)  A
5)  C
6)  D
7)  B
8)  C
9)  B
10) C

Explanation:

Q.1

      The Schrodinger wave equation is derived for the division of area or space around the nucleus into shells,subshells and orbitals.The spin quantum number (s) does not about area or space around the nucleus of an atom but it is related to spinning of electron around its own axis i.e; self rotation so Schrodinger did not derived spin quantum number from his wave equation.

Q.2

      The formula is used to calculate total number of electrons in any shell is following

          2n^2

     n = shell number

If n = 5 

Then

Total electrons in 5th shell

= 2(5)^2 = 2(25) = 50 electrons

Q.3

      2l + l is the formula used to calculate number of orbitals in any subshell(azimuthal quantum number(l))

Q.4

      The electronic configuration of Fluorine (F) atom can be write without applying Hund's rule.Just try it yourself you will get the correct electronic configuration without applying Hinds rule

Q.5 

      The orientation of orbitals can be determined by using magnetic quantum number(m)

Q.6
          n        l       n+l
  3d    3       2      3+2= 5
  4s     4       0      4+0= 4
  5p    5       1      5+1= 6
  4f     4       3      4+3= 7

Q.7
    The electronic configurations
 Zn = [Ar] 3d^10 4s^2
 Cu = [Ar] 3d^10 4s^1
 Ca = [Ar] 4s^2
 Cl = [Ne] 3s^2 3p^5
    So its Cu which contains least( only one) electron in its outermost 4th shell

Q.8
     The volume of space in which there is more than 95% chance of finding an electron is called atomic orbital

Q.9
    According to n+l rule the next higher energy level after 5p is 6s

Q.10
     The shape of different sunshells
    Subshell                     Shape
         s                               Spherical
         p                              Dumble
         d                              Bilobed Dumble
         f                               Trilobed Dumble