Structure of atom practice · Medium

What will be the ratio of the wavelength of the first lineto that of the second line of Paschen series of ${H}$ atom?

With respect to atomic spectrum, each line in the Lyman series is due to electrons returning

The decreasing order (highest first) from the values of ${e} / {m}$ (charge/mass) for electron $(e),$ proton $(p)$, neutron $(n)$ and alpha particle $(\alpha)$ is

Ratio of the radius of first orbit of $\mathrm{Li}^{2+}$ to the third orbit of $\mathrm{He}^{+}$ions will be

Calculate the energy of ${Li}^{+2}$ atom for $2^{\text {nd}}$ excited state.

The correct set of quantum numbers for $4 d$-electrons are

Energies of 2S orbital in IA group is

Compared to mass of lightest nucleus the mass of an electron is only:

The total number of angular nodes and radial nodes present in 3p orbital

The fraction of volume occupied by the nucleus with respect to the total volume of an atom is

The de-Broglie wavelength of the electron in the ground
state of hydrogen atom is (KE = 13.6 eV)

A sample of hydrogen atoms containing all the atoms in a particular excited state absorb radiations of a particular wavelength by which the atoms get excited to another excited state. When the atoms finally de-excite to the ground state, they emit the radiations of 10 different wavelengths. Out of these 10 radiations, 7 have wavelengths shorter than the absorbed radiation and 2 have wavelength longer than the absorbed radiation. The orbit number for the initial excited state of atoms is

The wave number of first line of Balmer series of Hydrogen is $15200\,\,c{m^{ - 1}}$. The wavenumber of the first line of $15200\,c{m^{ - 1}}$ ion is

A dust particle has mass equal to $10^{-11} \mathrm{~g}$, diameter $10^{-4} \mathrm{~cm}$ and velocity $10^{-4} \mathrm{~cm} \mathrm{~s}^{-1}$. The error in measurement of velocity is $0.1 \%$. What will be the uncertainty in its position?

Evaluate the following statements related to group 14 elements for their correctness.

(A)Covalent radius decreases down the group from $\mathrm{C}$ to $\mathrm{Pb}$ in a regular manner.

(B) Electronegativity decreases from $\mathrm{C}$ to $\mathrm{Pb}$ down the group gradually.

(C) Maximum covalence of $\mathrm{C}$ is 4 whereas other elements can expand their covalence due to presence of $d$ orbitals.

(D) Heavier elements do not form $\mathrm{p} \pi-\mathrm{p} \pi$ bonds.

(E) Carbon can exhibit negative oxidation states.
Choose the correct answer from the options given below:

Which one of the following is not the characteristic of Planck's quantum theory of radiation?

In the ground state of $\mathrm{C}{\mathrm{u}^ + }$, the number of shell occupied, sub-shells occupied, fillied orbitals and unpaired electrons respectively are

Statement (S): Wavelength of I line of Humphrey series is more than I line of Lyman series in H-atom.

Explanation (E): $\Delta E=\frac{h c}{\lambda}.$

How many moles of electrons weigh one milligram?

Which shell would be the first to have ' $g$ ' sub-shell?

Among the following transitions in hydrogen and
hydrogen-like ion spectrum, which one emits light
of longest wavelength ?

Of the following transitions in hydrogen atom, the one which gives an absorption line of lowest frequency is :

The radiation having maximum wavelength is

The uncertainty in the position of an electron (mass $=$ $9.1 \times 10^{-28} {~g}$ ) moving with a velocity of $3.0 \times 10^4 {~cm} {~s}^{-1}$ accurate upto $0.011 \%$ will be

The electronic velocity in the fourth Bohr's orbit of hydrogen is v. The velocity of the electron in the first orbit would be:

Ratio of radii of second and first Bohr orbits of H – atom

Arrange $\alpha -$ particle $(\alpha )$, ,electron $({e^ - }),$ proton (p) and neutron (n) in increasing order of their e/m value

Choose the correct energy order for $2 s$ orbital

What will be the wave length of an electron moving with $\frac{1}{10}$ th of velocity of light?

According to Bohr's theory, the electronic energy of $\mathrm{H}$-atom in Bohr's orbit is given by