Atomic Structure

Consider the following pairs of electrons

(A) (a) $n=3,\ l=1,\ m_l=1,\ m_s=+\frac12$

(b) $n=3,\ l=2,\ m_l=1,\ m_s=+\frac12$

(B) (a) $n=3,\ l=2,\ m_l=-2,\ m_s=-\frac12$

(b) $n=3,\ l=2,\ m_l=-1,\ m_s=-\frac12$

(C) (a) $n=4,\ l=2,\ m_l=2,\ m_s=+\frac12$

(b) $n=3,\ l=2,\ m_l=2,\ m_s=+\frac12$

The pairs of electrons present in degenerate orbitals is/are :

The energy of one mole of photons of radiation of wavelength 300 nm is

(Given : $h=6.63\times10^{-34}$ J s, $N_A=6.02\times10^{23}\ \mathrm{mol^{-1}}$, $c=3\times10^8\ \mathrm{m\,s^{-1}}$)

The pair, in which ions are isoelectronic with $\mathrm{Al^{3+}}$ is :

The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is $x\times10^{-8}$ m. The value of $x$ is ______. (Nearest Integer)

(Given : Energy of the electron in the first shell of the hydrogen atom is $-2.2\times10^{-18}$ J; $h=6.63\times10^{-34}$ Js and $c=3\times10^8\ \mathrm{ms^{-1}}$)

The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is:

[Given: The threshold frequency of platinum is $1.3\times10^{15}\ \mathrm s^{-1}$ and $h=6.6\times10^{-34}$ J s.]

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is

If the radius of the 3$^{\rm rd}$ Bohr's orbit of hydrogen atom is $r_3$ and the radius of 4$^{\rm th}$ Bohr's orbit is $r_4$. Then :

The number of radial and angular nodes in 4d orbital are, respectively

If the uncertainty in velocity and position of a minute particle in space are, $2.4\times10^{-26}$ (m s$^{-1}$) and $10^{-7}$ (m) respectively. The mass of the particle in g is ______. (Nearest integer)

(Given : $h=6.626\times10^{-34}$ Js)

The 'f' orbitals are half and completely filled, respectively in lanthanide ions

[Given : Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]

Consider the following set of quantum numbers.

	n	l	$m_l$
A.	3	3	−3
B.	3	2	−2
C.	2	1	+1
D.	2	2	+2

The number of correct sets of quantum numbers is ______.

Element "E" belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of the element, which is just above "E" in the group is

If the work function of a metal is $6.63\times10^{-19}$J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ______ nm. (Nearest integer)

[Given : h = $6.63\times10^{-34}$J s, and c = $3\times10^8$ m s$^{-1}$]

Consider the following statements :

(A) The principal quantum number 'n' is a positive integer with values of 'n' = 1, 2, 3, ...

(B) The azimuthal quantum number '$l$' for a given 'n' (principal quantum number) can have values as '$l$' = 0, 1, 2, .... n

(C) Magnetic orbital quantum number '$m_l$' for a particular '$l$' (azimuthal quantum number) has $(2l+1)$ values.

(D) $\pm1/2$ are the two possible orientations of electron spin.

(E) For $l=5$, there will be a total of 9 orbital

Which of the above statements are correct ?

Which of the following statements are correct ?

(A) The electronic configuration of Cr is [Ar] 3d$^5$ 4s$^1$.

(B) The magnetic quantum number may have a negative value.

(C) In the ground state of an atom, the orbitals are filled in order of their increasing energies.

(D) The total number of nodes are given by $n-2$.

Choose the most appropriate answer from the options given below :

The electronic configuration of Pt (atomic number 78) is :

Which of the following is the correct plot for the probability density $\Psi^2(r)$ as a function of distance '$r$' of the electron from the nucleus for 2s orbital?

The number of radial nodes and total number of nodes in 4p orbital respectively are :

Which of the following sets of quantum numbers is not allowed ?

When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are ______.