Structure of atom practice · Mixed difficulty

The shape of $s$-orbital 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?

The probability of finding the electron in the orbital is

Assertion: Nuclear binding energy per nucleon is in the order ${ }_4^9 {Be}>{ }_3^7 {Li}>{ }_2^4 {He}$.

Reason: Binding energy per nucleon increases linearly with difference in number of neutrons and protons.

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?

Mass of neutron is … times the mass of electron

The emission spectrum of hydrogen is found to satisfy the expression for the energy change, ∆E (in joules), such that $\Delta E = 2.18 \times {10^{ - 18}}\left[ {\frac{1}{{n_1^2}} - \frac{1}{{n_2^2}}} \right]$ J, where, ${n_1} = 1,2,3,\; \ldots$ and ${n_2} = 2,3,4, \ldots$ The spectral lines correspond to Paschen series are

Statement (S): Dipositive zinc ion exhibits paramagnetism due to the loss of two electrons from $3 d$-orbitals of neutral atom.

Explanation (E): Paramagnetism is due to the presence of unpaired electron.

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

Statement (S): All the $d$-orbitals are identical in shape.

Explanation (E): All the $p$-orbitals are identical in shape.

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

Heisenberg’s uncertainty principle rules out the exact simultaneous measurement of

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

In hydrogen spectrum least energetic transition of electrons are found in:

If the value of azimuthal quantum number is 3 , the possible values of magnetic quantum number would be:

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