Atomic Structure - Multiple Choice Questions

1. Any p-orbital can accommodate up to

a. four electrons
b. two electrons in parallel groups
c. six electrons
d. two electrons with opposite spins
(JEE 1983)

Answer ( c )

2. the principal quantum number of an atom is related to the

a. size of the orbital
b. spin angular momentum
c. orbital angular momentum
d. orientation of the orbital in space
(JEE 1983)

Answer: (a)

3. Correct set of four quantum numbers forhte valence (outmost) electron of rubidium 9Z = 37) is:

a. 5,0,0,+1/2
b. 5,1,0, +1/2
c. 5,1,1,+1/2
d. 6,0,0,+1/2
(JEE 1984)

Answer: (a)

4. Bohr model can explain:

a. the spectrum of hydrogen atom only
b. spectrum of an atom or ion containing one electron only.
c. the spectrum o hydrogen molecule
d. the solar spectrum
(JEE 1985)

Ans: (b)

5. Which one of the following sets of quantum numbers(n,l,ml, ms) represents as impossible arrangement?
a. 3,2,-2,1/2
b. 4,0,0,1/2
c. 3,2,-3,1/2
d. 5,3,0,-1/2
(JEE 1986)

Answe ( c )

Atomic Structure - True or False Type Questions

1. The outer electronic configuration of the ground state chromium atom is 3d⁴4s². (JEE 1982)

False

Chromium atomic number is 24.
Its our electronic configuration is 3d⁵4s² .

2. The energy of the electron in the 3d-orbital is less than that in the 4s-orbital in the hydrogen atom. (JEE 1983)

Ans: True. (Think what is the explanation)

Atomic Structure - 11 - Fill in the Blanks Type

1. The mass of a hydrogen atom is ------------------ kg. (JEE 1982)

answer: 1.66*10^-27 kg

2. When there are two electrons in the same orbital, they have ---------------- spins. (JEE 1982)

Answer: opposite or antiparallel

3. Isotopes of an element differ in the number of ______________ in their nuclei. (JEE 1982)

Anwer: neutrons




4. Elements of same mass number but of different atomic numbers are known as ----------.
(JEE 1983)

Answer: isobars


5. Fill in the blanks choosing appropriate words given with brackets)
the uncertainty principle and the concept of wave nature of matter were proposed by ----------------- and -------------------- respectively
(Heisenberg, Schrodinger, Maxwell, de Broglie)
(JEE 1988)

Answer: Heisenberg, de Broglie