If the wavelength of an electromagnetic radiation is 2000 Å, what is its energy in ergs?
9.94 × 10-12
9.94 × 10-19
4.97 × 10-12
4.97 × 10-19
Which one of the following statements is correct?
The radius (R) of a nuclide of mass number A is given by the equation R = R0(A)1/2 (R0 = constant)
7N15 and 8O16 are isobars
The end product nuclide in thorium (4n) series is 83Bi209
20Ca40 has magic number of protons and magic number of neutrons
6C12 and 1T3 are formed in nature due to the nuclear reaction of neutron with
7N14
6C13
2He4
3Li6
The atomic numbers of elements X,Y and Z are 19, 21 and 25 respectively. The number of electrons present in the M-shell of these elements follow the order
Z > X > Y
X > Y > Z
Z > Y > X
Y > Z > X
An electron is moving in Bohr's fourth orbit. Its de-Broglie wave length is λ. What is the circumference of the fourth orbit ?
2/λ
2λ
4λ
4/λ
Which of the following is correct?
1H1 and 2He3 are isotopes
6C14 and 7N14 are isotopes
19K39 and 20Ca40 are isotones
9F19 and 11Na24 are isodiaphers
What is the correct order of spin only magnetic moment (in BM) of Mn2+, Cr2+ and V2+ ?
Mn2+ > V2+ > Cr2+
V2+ > Cr2+ > Mn2+
Mn2+ > Cr2+ > V2+
Cr2+ > V2+ > Mn2+
C.
Mn2+ > Cr2+ > V2+
Spin only magnetic moments depend upon the number of unpaired electrons, more the number of unpaired electron, greater wtll be the spin only magnetic moment.
25Mn = 1s2, 2s2 2p6, 3s2 3p6 3d5, 4s2
Mn2+ = 1s2, 2s2 2p6, 3s2 3p6 3d5, 4s0
Number of unpaired electrons = 5
24Cr = 1s2, 2s2 2p6, 3s2 3p6 3d5, 4s1
Cr2+ = 1s2, 2s2 2p6, 3s2 3p6 3d4, 4s0
Number of unpaired electrons = 4
23V = 1s2, 2s2 2p6, 3s2 3p6 3d3, 4s2
V2+ = 1s2, 2s2 2p6, 3s2 3p6 3d3, 4s0
Number of unpaired electrons = 3
So, the correct order of spin only magnetic moment is
Mn2+ > Cr2+ > V2+
The energy of a photon is 3 × 10-12 ergs. What is its wavelength in nm ?
(h = 6.62 × 10-27 ergs ; c = 3 × 1010 cm/s)
662
1324
66.2
6.62
Which of the following is not correct ?
Nuclei of atoms participate in nuclear reactions
20Ca40 and 18Ar40 are isotones
1 amu of mass defect is approximately equal to 931.5 MeV.
Uranium (U238) series is known as (4n + 2) series.