Reasons of Stability

Q. Which of the following orbital has spherical symmetry:

1. $s$ orbital
2. $p$ orbital
3. $d_{xy}$ orbital
4. $d_{z^2}$ orbital

Q. The orbital diagrams of two atoms 'X' and 'Y' are given. Which of the following subshell will be more stable

1. For X, exchange energy is maximum and have more stability
2. For X, exchange energy is minimum and has more stability
3. For Y, exchange energy is maximum and has more stability
4. For Y, exchange energy is minumum and has more stability

Q. What is the maximum number of electrons present in an orbit whose angular momentum is $\frac{3h}{\pi }$?

1. $72$

2. $64$

3. $36$

4. $81$

Q. A gas of hydrogen-like ions is prepared in a particular excited. State A. It emits photons having wavelength equal to the wavelength of the first line of the Lyman series together with photons of five other wavelengths. Identify the gas and find the principal quantum number of the state A.

Q. If a photon of energy $14$ eV is incident on an H-atom, what is true?

1. Atom will be ionised and electron will have a kinetic energy of $0.4$ eV
2. Atom will be ionised and electron will have a kinetic energy of $14$ eV
3. None of these
4. Photon passes through atom without interacting with it

Q. $E_n=-313.6/n^2$ $kcal/mol$. If the value of $E=-34.84$ $kcal/mol$, to which value does '$n$' correspond?

1. $4$
2. $3$
3. $2$
4. $1$

Q. The average life of an excited state of hydrogen atom is of the order of ${10}^{-8}sec$. The number of revolutions made by an electron when it returns from $n=2$ to $n=1$ is:

1. $22.8\times {10}^6$
2. $2.82\times {10}^6$
3. $8.23\times {10}^6$
4. $2.28\times {10}^6$

Q. Which of the following values corresponds to the value of energy required to remove the second electron from the ground state of helium atom?

1. $-13.6eV$
2. $-27.2eV$
3. $-6.8eV$
4. $-54.4eV$

Q. A major line in an atomic emission spectrum occurs at $450$ nm. Find the energy decrease, as this photon is emitted.

Q. A source of light having wavelength $\lambda$ ejects photo electron with maximum kinetic energy $1eV$. On irradiating same metal with wavelength $1/3$, the eject photoelectron posses kinetic energy of $4eV$. The work function of metal is :

1. $2eV$
2. $1eV$
3. $3eV$
4. $0.5eV$