In hydrogen atom, an electron is transferred from an orbit of radius 1.3225 nm to another orbit of radius 0.2116 nm . What is the energy (in J ) of emitted radiation?

The radius of second orbit of hydrogen atom is same as that of orbit ( $n$ ) of an ion ( $x$ ), $n$ and $x$ are respectively.

An electromagnetic radiation of wavelength 331.5 nm is made to strike the surface of a metal. Electrons are emitted with a kinetic energy of $12 \times 10^5 \mathrm{~J} \mathrm{~mol}^{-1}$. The work function (in eV ) of the metal is $\left(h=6.63 \times 10^{-34} \mathrm{Js}, N_A=6 \times 10^{23} \mathrm{~mol}^{-1}\right)$

In the atomic spectrum of hydrogen, the wavelengths of the spectral lines corresponding to electronic transitions (i) $n=4$ to $n=2$ and (ii) $n=3$ to $n=1$ are $\lambda_1$ and $\lambda_2 \mathop {\rm{A}}\limits^{\rm{o}}$ respectively. The value of ( $\lambda_1-\lambda_2$ ) (in cm ) is ( $R_{\mathrm{H}}=$ Rydberg constant)

Work functions of four metals $M_1, M_2, M_3$ and $M_4$ are $4.8,4.3,4.75$ and 3.75 eV respectively. The metals which do not show photoelectric effect when light of wavelength 310 nm falls on the metals are

The energy associated with electron in first orbit of hydrogen atom is $-2.18 \times 10^{-18} \mathrm{~J}$. The frequency of the light required (in Hz ) to excite the electron to fifth orbit is ( $h=6.6 \times 10^{-34} \mathrm{Js}$ )

In $\mathrm{Sr}(Z=38)$, the number of electrons with $l=0$ is $x$, number of electrons with $l=2$ is $y \cdot(x-y)$ is equal to ( $l=$ Azimuthal quantum number)

The electron in hydrogen atom undergoes transition from higher orbits to an orbit of radius 476.1 pm . This transition corresponds to which of the following series?

Identify the incorrect statement from the following?

The radius of stationary state $(n=2)$ of hydrogen atom is $x \mathrm{pm}$. The radius of stationary state $(n=3)$ of $\mathrm{He}^{+}$ion (in pm) is

When electromagnetic radiation of wavelength 310 nm falls on the surface of a metal having work function 3.55 eV , the velocity of photoelectrons emitted is $x \times 10^5 \mathrm{~ms}^{-1}$. The value of $x$ is (Nearest integer) $\left(m_e=9 \times 10^{-31} \mathrm{~kg}\right)$

Two statements are given below :

Statement I : In H atom, the energy of $2 s$ and $2 p$ orbitals is same.

Statements II : In He atom, the energy of $2 s$ and $2 p$ orbitals is same.

The correct answer is

A 100 W bulb emits light of wavelength

$x \mathop {\rm{A}}\limits^{\rm{o}} $. What is the value of $x$, if the number of photons emitted is $2.0 \times 10^{20} \mathrm{~s}^{-1}$ ?

$ \left(h=6.63 \times 10^{-34} \mathrm{Js}, 1 \mathrm{~W}=1 \mathrm{Js}^{-1}\right) $

The ratio of the difference in energy between the first and second Bohr orbits to that between the second and third orbit is

In the reaction I and II the covalencies of Be and Al in $X$ and $Y$ are respectively

I. $\mathrm{Be}(\mathrm{OH})_2+\underset{\text { (Excess) }}{\mathrm{NaOH}} \longrightarrow X$

II. $\mathrm{Al}(\mathrm{OH})_3+\underset{\text { (Excess) }}{\mathrm{NaOH}} \longrightarrow Y$

The energy of second orbit of hydrogen atom is $-5.45 \times 10^{-19} \mathrm{~J}$. What is the energy of first orbit of $\mathrm{Li}^{2+}$ ions (in J)?

The number of electrons with $(n+l)$ values equal to 3,4 and 5 in an element with atomic number $(Z) 24$ are respectively

( $n=$ principal quantum number and $l=$ azimuthal quantum number)

What is the approximate angular momentum (in J s ) of electron in hydrogen atom in its ground state?

$ \left(h=6.625 \times 10^{-34} \mathrm{~J} \mathrm{~s}\right) $

The energy of electron in hydrogen atom when present in $n=1, n=2$ and $n=3$ will be in the ratio of

The radius of first Bohr orbit of hydrogen atom is same as that of orbit $(n)$ of hydrogen like species $X .(n)$ and $X$ respectively are

Identify the impossible quantum number set for the electron from the following.

The hybridisations of the central atom in the molecules $\mathrm{BF}_3, \mathrm{BeF}_2, \mathrm{BrF}_3$ are respectively.

When compared with alkaline earth metals, the alkali metals have

$\mathrm{Cr}^{2+}$ and $\mathrm{Mn}^{3+}$ do possess $d^4$ electronic configuration. So,

Consider the following.

I. The electron spin quantum number describes the orientation of the spin of the nucleus with respect to the magnetic field.

II. The orbitals represented by the quantum numbers $n=3, l=2, m=+2$ and $n=3, l=2, m=-2$ have the same energy.

III. The energy of a photon is directly proportional to wavelength but inversely proportional to wave number.

IV. Lyman series of lines appear in ultra-violet region.

The correct statements are

Choose the correct statements in reference to the photoelectric effect.

(A) There is no time lag between the striking of light and ejection of electrons from the metal surface.

(B) The number of electrons ejected is independent of the intensity of light.

(C) The elements $\mathrm{K}, \mathrm{Rb}$ and Cs can show photoelectric effect when exposed to the beam of light.

The maximum number of orbitals present in $n=4$ energy level of an atom and the maximum number of electrons with spin value $+\frac{1}{2}$ in the same orbitals are respectively

The approximate ratio of the speed of light in vacuum to that of an electron in the first Bohr orbit of hydrogen atom is

If the radius and energy of the second Bohr orbit of hydrogen atom is $r_2$ and $E_2$. respectively. The radius and energy of the third Bohr orbit will be $\_\_\_\_$ respectively.

When a radiation of 300 nm is shined on five metals, namely $\mathrm{Li}, \mathrm{Mg}, \mathrm{Ag}, \mathrm{Cu}$ and K , the number of metals that show photoelectric effect are

If the uncertainty in velocity is $\frac{1}{2 m} \sqrt{\frac{h}{\pi}}$, then the ratio of uncertainty in position and momentum is

The total number of spectral lines observed when electron returns from the 6th shell to the 2nd shell in hydrogen atom is

The orbital angular momentum of an electron in $d$-orbital is equal to

In hydrogen atom, the minimum energy required to excite an electron from 2nd orbit to the 3rd orbit is

The velocity $(v)$ of de-Broglie wave is given by

$ \left[\begin{array}{l} v=\text { frequency } \\ m=\text { mass } \\ C=\text { velocity } \text { of } \text { light } \end{array}\right] $

The maximum number of possible electrons in a subshell with $n=3$ and $l=2$ is

The uncertainty in position and velocity of a particle in motion are $1 \times 10^{-8} \mathrm{~m}$ and $6.627 \times 10^{-20} \mathrm{~m} / \mathrm{s}$, respectively. The mass of the particle is ( $h=6.627 \times 10^{-34} \mathrm{Js}$ )

Given the ratio of kinetic energy of electron in two orbitals is $16: 9$. Calculate the ratio of wavelength of electron waves?

Which of the following results is not true about photoelectric effect?

Which of the following statements is not true about Thomson's model of atom?

Which of the following statements is not the result of cathode ray discharge tube experiment with perforated anode?

The degeneracy of the level of hydrogen atoms that contain the energy of $\left(\frac{-R_{\mathrm{H}}}{16}\right)$ is

Wavelength of $\mathrm{H}^{+}$ion with kinetic energy 1.65 eV is (mass of proton $=1.6726 \times 10^{-27} \mathrm{~kg}$ )