Structure of atom practice · Mixed difficulty

When 3d-orbital is complete, the newly entering electron goes into:

The total number of nodes are given by

The quantum number which is responsible for the size of electron cloud is

The uncertainty in momentum of an electron is $1 \times {10^{ - 5}}$  kg m/s. the uncertainty in its position will be $(h = 6.62 \times {10^{ - 34}}$  kg ${\mathbf{m}^2}/\mathbf{s})$

Probability of finding an electron at the nodal surface is:

Statement – I: Kinetic energy of photoelectrons increases with increase in the frequency of incident radiation.

Statement – II: The number of photoelectrons ejected increases with increase in intensity of incident radiation.

The number of orbitals having $(n+l) < 5$ is

Which of the following set a of quantum numbers is correct for an electron in 4f orbital?

Atoms consist of electrons, protons and neutrons. If the mass attributed to neutron was halved and that attributed to the electrons was doubled, the atomic mass of ${\mathrm{\;}_6}{\mathrm{C}^{12}}$ would be approximately:

Compared with an atom of atomic weight 12 and atom ic number 6 , the atom of atomic weight 13 and atom ic number 6

When a certain metal was irradiated with light of frequency $4.0 \times 10^{16} \mathrm{~s}^{-1}$, the photoelectrons emitted has three times the kinetic energy as the kinetic energy of photoelectrons emitted when the metal was irradiated with light of frequency $2.0 \times 10^{16} \mathrm{~s}^{-1}$ Calculate the critical frequency $\left(v_0\right)$ of the metal.

Which of the following electromagnetic radiation have greater frequency?

An excited state of $\mathrm{H}$ atom emits a photon of wavelength $\lambda$ and returns in the ground state, the principal quantum number of excited state is given by :

Choose the incorrect statement(s):

Number of spectral lines falling in Balmer series when electrons are de-excited from $n^{\text {th }}$ shell will be given as

The total number of protons in $8.4 \mathrm{~g}$ of $\mathrm{MgCO}_3$ is $\left(N_{\mathrm{A}}=6.02 \times 10^{23}\right)$

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

In which of the orbit of $\mathrm{H}{\mathrm{e}^ + },$ the angular momentum of the electron in $h/2\pi ?$

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

Uncertainty in the position of an electron $\left( {\mathrm{mass} = 9.1 \times {{10}^{ - 31}}\mathrm{kg}} \right)$ moving with a velocity 300 $\mathrm{m}{\mathrm{s}^{ - 1}}$ accurate upon 0.001% will be
$\left( {h = 6.63 \times {{10}^{ - 34}}\mathrm{\;Js}} \right)$

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

Consider the following statements : 1.Electron density in xy plane in $3{d_{{x^2} - {y^2}}}$ orbital is zero 2.Electron density in xy plane in $3{d_{{z^2}}}$ orbital is zero 3.2s orbital has only one spherical node 4.For $2{p_z}$ orbital yz is the nodal plane The correct statements are

Positronium is a species consisting of an electron bound to a positron. What would be the radius of its first excited state?

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

Statement (S): ${ }_{24} \mathrm{Cr}$ has more paramagnetic nature than ${ }_{25} \mathrm{Mn}$.

Explanation (E): $\mathrm{Cr}$ has more number of unpaired electrons than $\mathrm{Mn}$.

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

The number of spherical nodes in 3p orbitals is

Energies of 2S orbital in IA group is

$\mathrm{Co}^{3+}, \mathrm{Mn}^{+}, \mathrm{Fe}^{2+}$ and $\mathrm{Cr}$ are isoelectronic (24 electrons) in each. Thus, EC are identical in