Question 2 :
The electronic configuration of $He$ is $2$ and that of oxygen is:
Question 3 :
A 3d electron (s = + 1/2) can have a magnetic quantum number of:<br/>
Question 4 :
The atomic number of an element whose differentiating electron enters in a d sub-shell:
Question 7 :
The energy of hydrogen atom in $n^{th}$ orbits is $E_n$, then the energy in $n^{th}$ orbit of single ionised helium atom will be :
Question 9 :
Which of the following quantum number determines the direction of spin of an electron?
Question 10 :
According to the Bhor Theory , which of the following transitions in the hydrogen atom will give rise to the least energetic photon ?
Question 11 :
The emission spectrum of hydrogen discovered first and the region of the electromagnetic spectrum in which it belongs, respectively are :
Question 13 :
Calculate the wavelength and energy of radiation emitted for the electronic transition from infinity to stationary state of the hydrogen.
Question 14 : For given energy of photon, $E=3.03\times 10^{-19}J$ corresponding wavelength will be: <div>$(h=6.6\times { 10 }^{ -34} sec$, $C=3\times { 10 }^{ 8 }m/sec.)$</div>
Question 15 :
An electron is in one of the $3d$-orbitals. What are the possible values of n, l, and m for this electron?
Question 16 :
A photon of radiation of wavelength 600 nm has an energy E. The wavelength of photon of radiation having energy 0.25 E is:
Question 17 :
The number of electrons in an atom is equal to number of
Question 18 :
The quantum number which determines the energy of a sublevel is:
Question 19 :
The energy of second orbit of hydrogen is equal to the energy of:
Question 20 :
A freshly prepared radioactive source of half-life $2 h$ emits radiation of intensity which is $64$ times the permissible safe level. The minimum time after which it would be possible to work safely with this source is<br>
Question 21 :
Arrange the following set of quantum numbers having highest energy of an electron.<br>(p) $n = 4$ $l = 1$ $m=+1$ $s = +\dfrac{1}{2}$<br>(q) $n = 4$ $l = 2$ $m=-1$ $s = -\dfrac{1}{2}$<br>(r) $n = 3$ $l = 2$ $m=0$ $s = +\dfrac{1}{2}$<br>(s) $n = 3$ $l = 1$ $m=+1$ $s = -\dfrac{1}{2}$
Question 22 : In an atom, an electron is moving with a speed of $600\ m/s$ with an accuracy of $0.005\%$. Certainty with which the position of the electron can be located is:<div><br/>($h=6.6 \times 10^{-34}\ kg\ m^{2}s^{-1}$ mass of elecrtron $m_{e}=9.1 \times 10^{-31}\ kg$)</div>
Question 23 :
When the electron of a hydrogen atom jumps from $n = 4$ to $n = 1$ state, the number of spectral lines emitted will be:
Question 24 : The radial wave equation for hydrogen atom is<br/> $\Psi =\dfrac { 1 }{ 16\sqrt { \pi } } { \left( \dfrac { 1 }{ { a }_{ 0 } } \right) }^{ { 3 }/{ 2 } }\left[ \left( x-1 \right) \left( { x }^{ 2 }-8x+12 \right) \right] { e }^{ { -x }/{ 2 } }$<br/><br/><div>where, $x={ 2r }/{ { a }_{ 0 } }$; ${ a }_{ 0 }=$ radius of first Bohr orbit.<div><br/>The minimum and maximum position of radial nodes from nucleus are:</div></div>
Question 27 :
Find out the wavelength of the next line in the series having lines of spectrum of $H$-atom of wavelengths $656.46, 486.27, 434.17$ and $410.29 \ nm$.
Question 28 :
The electrons, identified by quantum numbers $n$ and $l$, (i) $n=4, l=1$, (ii) $n=4, l=0$, (iii) $n=3, l=2$, and (iv) $n=3, l=1$ can be placed in order of increasing energy, from the lowest to highest, as:
Question 30 : The de-Broglie wavelength of a $He$ - atom in a container at $300K$ is:<div>(Use v$_{avg})$<br/></div>
Question 31 :
The number of revolutions of an electron in the second Bohr orbit in one second is:<br>
Question 32 :
Which of the following quantum numbers represent the impossible arrangement(s) of $n,\;l,\;m_{l},\;m_{s}$ respectively?<br/>
Question 33 :
$H$-atoms in ground state $(13.6eV)$ are excited by monochromatic radiations of photon of energy $12.1eV$. The number of spectral lines emitted in $H$-atom will be:<br>
Question 34 :
In order to get half velocity of electrons in second case, the applied potential will be:
Question 35 :
The maximum number of electrons that can be filled in the shell with the principal quantum number $n=4$ is:
Question 36 :
The correct Schrodinger's wave equation for a electron with total energy E and potential energy V is given by
Question 37 : Uncertainty in the position of an electron $(mass=9.1\times 10^{-31}kg)$ moving with a velocity $300ms^{-1}$ accurate upon 0.001% will be:<div>$[h=6.63\times 10^{-34}J-s]$ <br/></div>
Question 38 :
Which of the following sets of quantum numbers is correct for an electron in $3d$ orbital?
Question 39 :
Uncertainty in position of a hypothetical subatomic particle is 1 $A^o$ and uncertainty in velocity is $\frac{3.3}{4\pi}\times 10 ^{5}$ m/s. Then the mass of the particle is approximately: $[h = 6.6\times10^{-34} Js]$<br/>
Question 40 :
If the radius of first Bohr orbit of H atom is 0.53 $\dot{A}$, the radius of third orbit is:<br>
