Atomic Structure - Physical Chemistry - Chemistry Previous Year Questions

The orbital angular momentum of an electron in $d$-orbital is equal to

The total number of spectral lines observed when electron returns from the 6th shell to the 2nd shell in hydrogen atom is

In hydrogen atom, the minimum energy required to excite an electron from 2nd orbit to the 3rd orbit is

The velocity $(v)$ of de-Broglie wave is given by

$$\left[\begin{array}{l} v=\text { frequency } \\ m=\text { mass } \\ C=\text { velocity } \text { of } \text { light } \end{array}\right]$$

Consider the following.

I. The electron spin quantum number describes the orientation of the spin of the nucleus with respect to the magnetic field.

II. The orbitals represented by the quantum numbers $n=3, l=2, m=+2$ and $n=3, l=2, m=-2$ have the same energy.

III. The energy of a photon is directly proportional to wavelength but inversely proportional to wave number.

IV. Lyman series of lines appear in ultra-violet region.

The correct statements are

What is the approximate angular momentum (in J s ) of electron in hydrogen atom in its ground state?

$$\left(h=6.625 \times 10^{-34} \mathrm{~J} \mathrm{~s}\right)$$

The energy of electron in hydrogen atom when present in $n=1, n=2$ and $n=3$ will be in the ratio of

$\mathrm{Cr}^{2+}$ and $\mathrm{Mn}^{3+}$ do possess $d^4$ electronic configuration. So,

The radius of first Bohr orbit of hydrogen atom is same as that of orbit $(n)$ of hydrogen like species $X .(n)$ and $X$ respectively are

The hybridisations of the central atom in the molecules $\mathrm{BF}_3, \mathrm{BeF}_2, \mathrm{BrF}_3$ are respectively.

Identify the impossible quantum number set for the electron from the following.

When compared with alkaline earth metals, the alkali metals have

A 100 W bulb emits light of wavelength

$x \mathop {\rm{A}}\limits^{\rm{o}} $. What is the value of $x$, if the number of photons emitted is $2.0 \times 10^{20} \mathrm{~s}^{-1}$ ?

$$\left(h=6.63 \times 10^{-34} \mathrm{Js}, 1 \mathrm{~W}=1 \mathrm{Js}^{-1}\right)$$

The ratio of the difference in energy between the first and second Bohr orbits to that between the second and third orbit is

In the reaction I and II the covalencies of Be and Al in $X$ and $Y$ are respectively

I. $\mathrm{Be}(\mathrm{OH})_2+\underset{\text { (Excess) }}{\mathrm{NaOH}} \longrightarrow X$

II. $\mathrm{Al}(\mathrm{OH})_3+\underset{\text { (Excess) }}{\mathrm{NaOH}} \longrightarrow Y$

The number of electrons with $(n+l)$ values equal to 3,4 and 5 in an element with atomic number $(Z) 24$ are respectively

( $n=$ principal quantum number and $l=$ azimuthal quantum number)

The energy of second orbit of hydrogen atom is $-5.45 \times 10^{-19} \mathrm{~J}$. What is the energy of first orbit of $\mathrm{Li}^{2+}$ ions (in J)?

Which of the following statements is not true about Thomson's model of atom?

Which of the following statements is not the result of cathode ray discharge tube experiment with perforated anode?