PYQ NEET- Atoms And Nuclei L-6

Question: The total energy of an electron in an atom in an orbit is $-3.4 \mathrm{eV}$. Its kinetic and potential energies are, respectively.#

A) $3.4 \mathrm{eV},-6.8 \mathrm{eV}$

B) $3.4 \mathrm{eV}, 3.4 \mathrm{eV}$

C) $-3.4 \mathrm{eV},-3.4 \mathrm{eV}$

D) $-3.4 \mathrm{eV},-6.8 \mathrm{eV}$

Answer: (A) $3.4 \mathrm{eV},-6.8 \mathrm{eV}$#

Sol:#

Apply Bohr’s Atomic model for $\mathrm{H}$-atom $\mathrm{KE}=-\mathrm{T} . \mathrm{E}$ and $\mathrm{PE}=2 \mathrm{~T} . \mathrm{E}$

Given, T.E $=-3.4 \mathrm{eV}$ $\therefore \mathrm{KE}=+3.4 \mathrm{eV}$ and $\mathrm{PE}=-6.8 \mathrm{eV}$