JEE Advanced (Fill in the Blanks): Structure of Atom

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

Ans. 1.66 × 10^-27 Kg

Sol. 1.66 × 10^-27 Kg

Mass of hydrogen atom

= 0.166 × 10-23 g = 1.66 × 10-27 kg

Q.2. Isotopes of an element differ in the number of ............. in their nuclei. (1982 - 1 Mark)

Ans. neutrons 

Sol. neutrons 

Q.3. When there are two electrons in the same orbital, they have ............. spins. (1982 - 1 Mark) 

Ans. antiparallel or opposite

Sol. antiparallel or opposite

Q.4. Elements of the same mass number but of different atomic numbers are known as ............... . (1983 - 1 Mark) 

Ans. isobars

Sol.  isobars

Q.5. The uncertainty principle and the concept of wave nature of matter were proposed by ............... and ............... respectively. (Heisenberg, Schrodinger, Maxwell, de Broglie) (1988 - 1 Mark) 

Ans. Heisenberg, de-Broglie

Sol. Heisenberg, de-Broglie

Q.6. The light radiations with discrete quantities of energy are called ............... . (1993 - 1 Mark)

Ans. Photons

Sol. Photons

Q. 7. Wave functions of electrons in atoms and molecules are called ............... . (1993 - 1 Mark) 

Ans. oribtals

Sol. oribtals

Q.8. The 2p_x ,2p_y and 2p_z orbitals of atom have identical shapes but differ in their ............... . (1993 - 1 Mark)

Ans. orientation in space

Sol. orientation in space

Q. 9. The outermost electronic configuration of Cr is ............... . (1994 - 1 Mark)

Ans. 3d⁵ 4s¹

Sol. 4s¹, 3d⁵;
The electronic configuration of Cr is : 1s², 2s², 2p⁶, 3s², 3p⁶, 4s¹, 3d⁵.

∴ Outermost electronic configuration is 3d⁵, 4s¹.