Niobium (Nb) and ruthenium (Ru) have “x” and “y” number of electrons in their respective 4 d orbitals. The value of x+y is .
11
Nb (Z=41): [Kr] 4d45s1 ⇒ x=4
Ru (Z=44): [Kr] 4d75s1 ⇒ y=7
∴ x+y=11
Answer: 11
Compare the energies of following sets of quantum numbers for multielectron system. (A) n = 4, l = 1 (B) n = 4, l = 2 (C) n = 3, l = 1 (D) n = 3, l = 2 (E) n = 4, l = 0 Choose the correct answer from the options given below :
Match List I with List II Choose the correct answer from the options given below:
Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter 10-15 m is 109 ms-1 (nearest integer) [Given : mass of electron = 9.1 10-31 kg, Planck's constant (h) = 6.626 10-34 Js] (Value of = 3.14)
A hypothetical electromagnetic wave is shown below. [figure] The frequency of the wave is x 1019 Hz. x = (nearest integer)
Wavenumber for a radiation having 5800 Å wavelength is x 10 cm-1. The value of x is . (Integer answer)
Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is 1013 Hz (nearest integer). [Given : RH (Rydberg constant) = 2.18 10-18 J, h (Planck's constant) = 6.6 10-34 J. s.]
For hydrogen atom, energy of an electron in first excited state is -3.4 eV. K.E. of the same electron of hydrogen atom is x eV. Value of x is 10-1 eV. (Nearest integer)
The value of Rydberg constant (RH) is 2.18 10-18 J. The velocity of electron having mass 9.1 10-31 kg in Bohr's first orbit of hydrogen atom = 105 ms-1 (nearest integer).
In an atom, total number of electrons having quantum numbers n = 4, |ml| = 1 and ms = - 12 is .
The de-Broglie's wavelength of an electron in the 4th orbit is 0. (a0 = Bohr's radius)