JEE Advanced (True/False) Structure of Atom - Chapter-wise Tests for JEE

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

Ans. Sol. False : The outer electronic configuration of the ground state chromium atom is 3d⁵ 4s¹, as half filled orbitals are more stable than nearly half filled orbitals.

Q.2. Gamma rays are electromagnetic radiations of wavelengths of 10^-6 cm to 10^-5 cm. (1983 - 1 Mark)

Ans. Sol. False : Gamma rays are electr omagnetic radiati on s of wavelengths 10^-9 cm to 10^-10 cm.

Q. 3. The energy of the electron in the 3d-orbital is less than that in the 4s-orbital in the hydrogen atom. (1983 - 1 Mark)

Ans. Sol. True : Although energies of the s and p orbitals for the same principal quantum number are very close to each other;  the energy of the corresponding d orbitals is much higher. For example, the energy of 3d orbitals is much more than that of 3s and 3p; orbitals but less than 4s orbitals in case of H atom.

Q. 4. The electron density in the XY plane in 3d _{x²  - y²} orbital is zero. (1986 - 1 Mark)

Ans. Sol. False : The orbital 3d _{x²  - y²}  lie along X and Y axis where electron density is maximum.

Q. 5. In a given electric field, β-particles are deflected more than a-particles in spite of a-particles having larger charge. (1993 - 1 Mark)

Ans. Sol. True : β-particles are deflected more than a-particles because they have very-very large e/m value as compared to a-particles due to the fact that electrons are much lighter than He²⁺ species.