Structure of atom practice · Mixed difficulty

Angular momentum of an electron in an orbital is given by

If $e=1.60206 \times 10^{-19} {C}, \frac{e}{m}=1.75875 \times 10^{11} {Ckg}^{-1}$ then the mass of electron is

Assertion :- When we give electron beam of 10.60 eV energy on hydrogen sample it will
excite to first excited state.

Reason :- The difference between $n_2$ and $n_1$ is 10.2005 eV only.

The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' $\mathrm{A}$ ' $\times 10^{12}$ hertz and that has a radiant intensity in that direction of $\frac{1}{{ }^{\prime} \mathrm{B}^{\prime}}$ watt per steradian. 'A' and 'B' are respectively

The specific charge for positive rays is much less than the specific charge for cathode rays. This is because:

The number of nodal planes in a ${P_X}$ orbital is

Which one of the following is the set of correct quantum numbers of an electron in 3d orbital?

STATEMENT-1 : Emitted radiation will fall in visible range when an electron jump from $n=4$ to $n=2$ in ${H}$-atom.

STATEMENT-2 : Balmer series radiations belong to visible range for hydrogen atom only.

Splitting of spectral lines when atoms are subjected to strong electric field is called:

The Bohr's energy equation for H atom reveals that the energy level of a shell is given by $E = - 13.58/{n^2}\;\mathrm{eV}.$ The smallest amount that an H-atom will absorb, if in ground state is:

What is the mass of a photon of sodium light with a wavelength of 5890 ${A^0}?(h = 6.63\mathrm{ \times }{10^{ - 27}}erg - s)$

Which electronic level will allow the hydrogen atom to absorb photon but not to emit?

Assertion: The boundary surface for $|\psi|^2$ and $|\psi|$ are identical.

Reason : From the value of $|\psi|^2$ at different points within an atom, it is not possible to predict the region around the nucleus where electron will most probably be found.

Consider the following statements.
I. $|\psi|^2$ is a measure of electron density at a point in an atom.

II. Radial probability function $\left(=4 \pi r^2 R^2 \psi^2\right)$ gives the probability of finding the electron at a distance $r$ (atomic radius) from the nucleus regardless of direction.

III. The shape of an orbital is defined as a surface of constant probability density that encloses some large fractions of the probability of finding the electron.

Select the correct statements.

The number of molecules or ions from the following, which do not have odd number of electrons are _____
(A) $\mathrm{NO}_{2}$ $\quad$ (B) $\mathrm{ICl}_{4}^{-}$ $\quad$(C) $\mathrm{BrF}_{3}$ $\quad$ (D) $\mathrm{ClO}_{2}$ $\quad$ (E) $\mathrm{NO}_{2}^{+}$ $\quad$ (F) $\mathrm{NO}$

The frequency v of certain line of the Lyman series of the atomic spectrum of hydrogen satisfies the following conditions:
(i) It is the sum of the frequencies of another Lyman line and a Balmer line.
(ii) It is the sum of the frequencies of a certain line, a Lyman line, and a Paschen line.
(iii) It is the sum of the frequencies of a Lyman and a Paschen line but no Bracket line.
To what transition does v correspond?

Which of the following statement is not correct about the characteristics of cathode rays.

The best metal to be used for photoemission is:

S-I: Line spectrum of $\mathrm{Li}^{+2}$ and $\mathrm{He}^{+}$are identical.

S-II: Isoelectronic species produce identical spectrum.

If ${E_e},{E_\alpha}\,$ and ${E_p}$ represent the kinetic energies of an electron, alpha particle and a proton respectively, each moving with same de-Broglie wavelength then

The mass of electron moving with velocity of light is:

For a metal ion, the calculated magnetic moment is 4.90 BM. This metal ion has____number of unpaired electrons.

Which of the subshell has double dumb-bell shape?

Which of the following observations was not correct during Rutherford’s scattering experiment?

If the wavelength of an electromagnetic radiation is 2000Å, what is its energy in ergs?

Which d-orbital does not have four lobes?

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.

Which one is not true for the cathode rays?

The energy of electron in first orbit of $\mathrm{H}{\mathrm{e}^ + }$ is $\left( {{R_\mathrm{H}} = - 871.6 \times {{10}^{ - 20}}\mathrm{\;J}} \right).$ The energy of electron in the first orbit of H is:

According to Bohr’s theory, angular momentum of electron in N – shell is