Structure of atom practice · Medium

If the de-Broglie wavelength of a particle of mass $m$ is 100 times its velocity, then its value in terms of its mass ( ${m}$ ) and Planck's constant $(h)$ is

The number of electrons, protons and neutrons in a species are equal to 18, 16 and 16 respectively. Assign the proper symbol to the species.

The total number of nodes in a subshell are given by

Which of the following is correctly matched?

For a d – electron, the orbital angular momentum is

Which of the following is not permissible arrangement of electrons in an atom

Statement I: $\mathrm{Fe}^{3+}$ ion is more stable than $\mathrm{Fe}^{2+}$ ion in the gaseous state.
Statement II: $\mathrm{Fe}^{3+}$ ion has more number of unpaired electrons than $\mathrm{Fe}^{2+}$ ion.

Which of the following orbital have nodal plane in XY-plane?

In hydrogen atomic spectrum, a series limit is found at 12186.3 $c{m^{ - 1}}$. Then, it belongs to

The most probable radius (in pm) for finding the electron inHe ${ }^{+}$is:

Which of the following has the highest value of specific charge?

The momentum of a photon is $p,$ the energy associated with photon is given by:

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason
R.
Assertion A: Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.
Reason R : Energies of the orbitals in the same subshell decrease with increase in the atomic number.
In the light of the above statements, choose the correct answer from the options given below.

An electron revolves round $\mathrm{Li}^{2+}$ nucleus at a distance of $1.587\,\mathop {\text{A}}\limits^ \circ$. The speed of electron should be

Number waves in a Bohr orbit of H – atom is 3. Its potential energy would be

Select the correct statements from the following.

A. Atoms of all elements are composed of two fundamental particles.

B. The mass of the electron is $9.10939 \times 10^{-31} \mathrm{~kg}$.

C. All the isotopes of a given element show same chemical properties.

D. Protons and electrons are collectively known as nucleons.

E. Dalton's atomic theory, regarded the atom as an ultimate particles of matter.

Choose the correct answer from the options given below.

The de Broglie wavelength associated with a ball of mass $200 {~g}$ and moving at a speed of $5 {~m} / {h}$, is of the order of $\left({h}=6.625 \times 10^{-34} {Js}\right.$ )

The radii of an atom and atomic nucleus is of the order of

The wavelength of a spectral line emitted by hydrogen atom in the Lyman series is $\frac{{16}}{{15R}}\mathrm{cm}$. What is the value of ${n_2}$?(R=Rydberg constant)

What is the ratio of maximum $\lambda$ of Lyman and Balmer series

In Bohr's model of the hydrogen atom, let $r, v$ and $E$ represent the orbit radius, speed of an electron and the total energy of the electron, respectively. Which of following relation is proportional to the orbit number $n$ ?

The ratio of the radii of the first three Bohr orbits is :

The quantum number of four electrons are given below:
I. $n = 4,\,\,l = 2,\,\,{m_l} = - 2,\,\,{m_s} = - \frac{1}{2}$
II. $n = 3,\,\,l = 2,\,\,{m_l} = 1,\,\,{m_s} = + \frac{1}{2}$
III. $n = 4,\,\,l = 1,\,\,{m_l} = 0,\,\,{m_s} = + \frac{1}{2}$
IV. $n = 3,\,\,l = 1,\,\,{m_l} = 1,\,\,{m_s} = - \frac{1}{2}$
The correct order of their increasing energies will be

A dye absorb light of $\lambda=4530 \mathop {\text{A}}\limits^{\text{o}}$ and then fluorescence of $5080 \mathop {\text{A}}\limits^{\text{o}}$ Assuming that under given conditions $47 \% \mathrm{C}$ absorbed energy is re-emitted out as fluorescence, calculate ratio of quanta emitted out to the number of quanta absorb

If nucleus and atom are considered as perfect spheres with diameters $4 \times 10^{-15} \mathrm{~m}$ and $2 \times 10^{-10}$ $\mathrm{m}$, respectively, then the ratio of the volumes of nucleus and atom should be

Statement I : The amount of light emitted (intensity of radiation) from a black body and its spectral distribution depends only on its temperature
Statement II : 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

The total energy in $1^{\text {st }}$ orbit of hydrogen atom is given by

In cathode ray discharge tube experiment, when sufficiently high voltage is applied across the electrodes, current starts flowing through a stream of particles from negative electrode to positive electrodes. These particles are called

What is the de-Broglie wavelength (in ${nm}$ ) of an electron in the ground state of hydrogen atom is ?

$\text { [K.E. }=13.6 \,{eV} ; 1 \,{eV}=1.602 \times 10^{-19} {~J} \text { ] }$

Which of the following does not characterise X-rays?