Structure of atom practice · Mixed difficulty

What is the wavelength in $\mathrm{nm}$ of the spectral line associated with a transition from $n=3$ to $n=2$ for the $\mathrm{Li}^{2+}$ ion?

The energy of the electron in a hydrogen atom has a negative sign because

The momentum of a photon of frequency $5 \times {10^{17}}{\mathrm{s}^{ - 1}}$ is nearly:

Electromagnetic radiation with minimum wavelength is

The velocity of particle $A$ is $0.1 {~ms}^{-1}$ and that of particle $B$ is $0.05 {~ms}^{-1}$. If the mass of particle $B$ is five times that of particle ${A}$, then the ratio of de-Broglie wavelengths associated with the particles ${A}$ and ${B}$ is

Which of the following scientists explained his model on the basis of centrifugal force?

The uncertainties in the velocities of two particles A and B are 0.05 and 0.02 $\mathrm{m}{\mathrm{s}^{ - 1}}$ respecively. The mass of B is five times to that of mass A. What is the ratio of uncertainties $\left( {\frac{{\Delta {x_A}}}{{\Delta {x_B}}}} \right)$ in their positions?

Which of the following electronic transitions requires for the greatest quantity of energy be absorbed by a H-atom?

Assertion: All p-orbitals have only one planar node.

Reason: The number of radial nodes depends on the principal quantum number only.

The radius of which of the following orbit is same as that of first Bohr’s orbit of Hydrogen atom

The number of waves in an orbit are

When the azimuthal quantum number has a value of $l=1$, the shape of the orbital is:

The electron possesses wave properties was shown experimentally by:

As ‘n’ value increases de-broglie’s wavelength of electron

For which of the following species, Bohr’s theory doesn’t apply

Assertion :- A spectral line will be seen for a $2p_x – 2p_y$ transition.

Reason :- Only Balmer lines are observed in the visible region.

In order to designate an orbital n in an atom, the number of quantum number required are:

Thewavelength of a $150 \mathrm{~g}$ rubber ball moving with a velocity of $50 {~ms}^{-1}$ is :

The probability of finding out an electron at a point within an atom is proportional to the

Millikan performed an experiment method to determine which of the following?

Statement (S): Electronic configuration of ${ }_{23} \mathrm{V}^{3+}$ ion is $[\mathrm{Ar}]^{18} 3 d^2$ and not $[\mathrm{Ar}]^{18} 3 d^0 4 s^2.$

Explanation (E): $\mathrm{V}^{3+}$ ion is diamagnetic in nature.

Which of the following is not iso electronic with ${H}_2 {S}?$

How many neutrons are present in tritium nucleus?

The ratio of charge to mass of an electron in coulombs per gram was determined by J.J. Thomson. He determined this ratio by measuring the deflection of cathode rays in electric and magnetic fields. What value did he find for this ratio?

Calculate number of electron for which $n=4$ and ${S}=+\frac{1}{2}$

For hydrogen atom, the correct order of energy of orbitals is

Consider the following statements:

I. The speed of light does not depends upon the nature of the medium through which it passes.

II. The beam of light is deviated or refracted from its original path as it passes from one medium to another.

III. When a ray of white light is passed through a prism, the wave with shorter wavelength bends more than the one with a longer wavelength.

Choose the correct statements and select the correct option.

Which of the following phenomenon is responsible for the television pictures?

Assertion: The maximum number of eletrons in p & d subshells are 6 and 10 respectively.

Reason: The maximum number of electrons in the shell with prinicpal quantum number $n$ is equal to $2 n^2$.

Spin angular momentum of electron is given by