Structure of Atom

Maximum number of electrons in a subshell of an atom is determined by the following

1. 2 + 1
2. 4 - 2
3. 2n2
4. 4 + 2

Which of the following is not permissible arrangement of electrons in an atom ?

1. n = 5, = 3, m = 0, s = +1/2
2. n = 3, = 2, m = -3, s = -1/2
3. n = 3, = 2, m = -2, s = -1/2
4. n = 4, = 0, m = 0, s = -1/2

If uncertainty in position and momentum are equal, then uncertainty in velocity is

1. 1m h
2. h
3. 12m h
4. h2

The measurement of the electron position is associated with an uncertainty in momentum, which is equal to 1 10-18 g cm s-1. The uncertainty in electron velocity is (mass of an electron is 9 10-28 g)

1. 1 105 cm s-1
2. 1 1011 cm s-1
3. 1 109 cm s-1
4. 1 106 cm s-1

Consider the following sets of quantum numbers: array|c|c|c|c|c| & n & l & m & s \ (i) & 3 & 0 & 0 & +1/2 \ (ii) & 2 & 2 & 1 & +1/2 \ (iii) & 4 & 3 & -2 & -1/2 \ (iv) & 1 & 0 & -1 & -1/2 \ (v) & 3 & 2 & 3 & +1/2 \ array Which of the following sets of quantum numbers are not possible?

1. (i), (ii), (iii) and (iv)
2. (ii), (iv) and (v)
3. (i) and (iii)
4. (ii), (iii) and (iv)

The orientation of an atomic orbital is governed by

1. principal quantum number
2. azimuthal quantum number
3. spin quantum number
4. magnetic quantum number.

Given : The mass of electron is 9.11 10-31 kg, Planck constant is 6.626 10-34 J s, the uncertainty involved in the measurement of velocity within a distance of 0.1 A is

1. 5.79 105 m s-1
2. 5.79 106 m s-1
3. 5.79 107 m s-1
4. 5.79 108 m s-1

The energy of second Bohr orbit of the hydrogen atom is -328 kJ mol-1; hence the energy of fourth Bohr orbit would be

1. -41 kJ mol-1
2. -82 kJ mol-1
3. -164 kJ mol-1
4. -1312 kJ mol-1

The frequency of radiation emitted when the electron falls from n = 4 to n = 1 in hydrogen atom will be (Given ionization energy of H = 2.18 10-18 J atom-1 and h = 6.625 10-34 J s)

1. 1.54 1015 s-1
2. 1.03 1015 s-1
3. 3.08 1015 s-1
4. 2.00 1015 s-1

The radioactive isotope 6027Co which is used in the treatment of cancer can be made by (n, p) reaction. For this reaction the target nucleus is

1. 5928Ni
2. 5927Co
3. 6028Ni
4. 6027Co