Atoms practice · Mixed difficulty

Mosley measured the frequency $\left( f \right)$ of the characteristic $X$-rays from many metals of different atomic number $\left( \mathrm{Z} \right)$ and represented his results by a relation known as Mosley’s law. This law is (a, b are constants)

In the lowest energy level of hydrogen atom, the electron has the angular momentum

Assertion (A): According to classical theory, the proposed path of an electron in Rutherford atom model will be parabolic.

Reason (R): According to electromagnetic theory an accelerated particle continuously emits radiation.

The electric potential between a proton and an electron is given by $V = {V_0}\,\,\ln \,\,\frac{r}{{{r_0}}}$ , where ${r_0}$ is a constant. Assuming Bohr’s model to be applicable, write variation of ${r_n}$ with $n,n$ being the principal quantum number

Penetrating power of X-rays depends on

The value of structure constant is

Electrons in a certain energy level $n = {n_1}$, can emit $\mathrm{3}\,\mathrm{ spectral}\,\mathrm{ lines}$. When they are in another energy level, $n = {n_2}$. They can emit $\mathrm{6}\,\mathrm{ spectral}\,\mathrm{ lines}$. The orbital speed of the electrons in the two orbits are in the ratio

If wavelength corresponding to 2nd line of Lyman series is $\lambda$, then the wavelength corresponding to last line of Balmer series will be

Let ${\lambda _\alpha },{\lambda _\beta }$ and ${{\lambda '}_\alpha }$ denote the wavelengths of the $\mathrm{X}$-rays of the ${K_\alpha },{K_\beta }$ and ${L_\alpha }$ lines in the characteristic $\mathrm{X}$-rays for a metal. Then

Whenever a hydrogen atom emits a photon in the Balmer series

The ionization energy for second He electron is:

An $X$-ray tube is run at $50 \mathrm{~kV}$. The current flowing in it is $20 \mathrm{~mA}$. The power of the tube is:

When a hydrogen atom is raised from the ground state to an excited state

An electron in the $n = 1$ orbit of hydrogen atom is bounded by $13.6\,\,eV$. Energy requires to ionize it is

In Bohr’s model of hydrogen atom, let $PE$ represents potential energy and $TE$ the total energy. In going to a higher level

The ionization energy of the electron in the hydrogen atom in its ground state is $13.6\,\,eV$. The atoms are excited to higher energy levels to emit radiations of $\mathrm{6 }\,\mathrm{wavelengths}$. Maximum wavelength of emitted radiation corresponds to the transition between

In Bohr’s model of hydrogen atom, which of the following represents the variation of nth orbit radius with n?

The energy required to remove the electron from a singly ionized Helium atom is 2.2 times the energy required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is:

Which of the following is true

The specific charge of an electron is

$X$-rays emitted from a copper target and a molybdenum target are found to contain a line of wavelength $22.85 \mathrm{~nm}$ attributed to the $K_\alpha$ line of an impurity element. The $K_\alpha$ line's of copper $(Z=29)$ and molybdenum $(Z=42)$ have wavelengths $15.42 \mathrm{~nm}$ and $7.12 \mathrm{~nm}$ respectively. The atomic number of the impurity element is:

The equation $\lambda=\frac{1.227}{x} \mathrm{~nm}$ can be used to find the de- Broglie wavelength of an electron.
In this equation $x$ stands for:
Where m = mass of electron
P = momentum of electron
K = Kinetic energy of electron
V = Accelerating potential in volts for electron

According to Moseley’s law of $X$-rays the frequency $\left( v \right)$ of particular characteristic $X$-ray and the atomic number $\left( Z \right)$ of the element depend on each other as

A particle $A$ has a charge $q$ and particle $B$ has charge $4 q$ with each of them having the mass ${m}$. When they are allowed to fall from rest through the same potential difference, the ratio of their speeds $v_A: v_B$ will be

The ratio of the longest to shortest wavelengths in Lyman series of hydrogen spectra is

Maximum wavelength in Balmer series of hydrogen spectrum is (R : Rydberg constant)

The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the $5^{\text {th }}$ excited state of a hydrogen atom is :

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : The beam of electrons show wave nature and exhibit interference and diffraction.
Reason R : Davisson Germer Experimentally verified the wave nature of electrons.
In the light of the above statements, choose the most appropriate answer from the options given below:

Cathode ray tube is operating at $5\,KV$. Then the K.E. acquired by the electron is

Statement I: Bohr had to postulate that the electrons in stationary orbits around the nucleus do not radiate.
Statement II: According to classical physics all moving electrons radiate electromagnetic radiation.