Structure of Atom

Be2+ is isoelectronic with which of the following ions?

1. H+
2. Li+
3. Na+
4. Mg2+

What is the maximum number of electrons that can be associated with the following set of quantum numbers ? n = 3, l = 1 and m = -1

1. 4
2. 2
3. 10
4. 6

Based on equation E = -2.178 10-18 J ( Z2n2 ), certain conclusions are written. Which of them is not correct ?

1. Equation can be used to calculate the change in energy when the electron changes orbit.
2. For n = 1, the electron has a more negative energy than it does for n = 6 which means that the electron is more loosely bound in the smallest allowed orbit.
3. The negative sign in equation simply means that the energy of electron bound to the nucleus is lower than it would be if the electrons were at the infinite distance from the nucleus.
4. Larger the value of n, the larger is the orbit radius.

The value of Planck's constant is 6.63 10-34 J s. The speed of light is 3 1017 nm s-1. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of 6 1015 s-1 ?

1. 50
2. 75
3. 10
4. 25

According to law of photochemical equivalence the energy absorbed (in ergs/mole) is given as (h = 6.62 10-27 ergs, c = 3 1010 cm s-1, NA = 6.02 1023 mol-1)

1. 1.196 108
2. 2.859 105
3. 2.859 1016
4. 1.196 1016

The orbital angular momentum of a p-electron is given as

1. h 2
2. 3 h2
3. 32 h
4. 6 h2

Maximum number of electrons in a subshell with l = 3 and n = 4 is

1. 14
2. 16
3. 10
4. 12

The correct set of four quantum numbers for the valence electron of rubidium atom (Z = 37) is

1. 5, 1, 1, + 12
2. 6, 0, 0, + 12
3. 5, 0, 0, + 12
4. 5, 1, 0, + 12

According to the Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon ?

1. n = 6 to n = 1
2. n = 5 to n = 4
3. n = 6 to n = 5
4. n = 5 to n = 3

The total number of atomic orbitals in fourth energy level of an atom is

1. 8
2. 16
3. 32
4. 4

The energies E1 and E2 of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths i.e., 1 and 2 will be

1. 1 = 2
2. 1 = 2 2
3. 1 = 4 2
4. 1 = 12 2

If n = 6, the correct sequence for filling of electrons will be

1. ns (n-2)f (n-1)d np
2. ns (n-1)d (n-2)f np
3. ns (n-2)f np (n-1)d
4. ns np (n-1)d (n-2)f

A 0.66 kg ball is moving with a speed of 100 m/s. The associated wavelength will be (h = 6.6 10-34 J s)

1. 6.6 10-32 m
2. 6.6 10-34 m
3. 1.0 10-35 m
4. 1.0 10-32 m

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

The value of Planck's constant is 6.63 10-34 J s. The velocity of light is 3.0 108 m s-1. Which value is closest to the wavelength in nanometers of a quantum of light with frequency of 8 1015 s-1 ?

1. 2 10-25
2. 5 10-18
3. 4 101
4. 3 107

In hydrogen atom, energy of first excited state is -3.4 eV. Then find out K.E. of same orbit of hydrogen atom

1. +3.4 eV
2. +6.8 eV
3. -13.6 eV
4. +13.6 eV

23592U, nucleus absorbs a neutron and disintegrates into 13954Xe, 9438Sr and x so, what will be product x?

1. 3-neutrons
2. 2-neutrons
3. -particle
4. -particle

The following quantum numbers are possible for how many orbitals : n = 3, l = 2, m = +2 ?

1. 1
2. 2
3. 3
4. 4

If a abX species emits first a positron, then two and two particles and in the last, one is also emitted and gets converted to cdY species. So correct relation is

1. c = a - 12, d = b - 5
2. c = a - 5, d = b - 1
3. c = a - 6, d = b - 0
4. c = a - 4, d = b - 2

For given energy, E = 3.03 10-19 Joules corresponding wavelength is (h = 6.626 10-34 J sec, c = 3 108 m/sec)

1. 65.6 nm
2. 6.56 nm
3. 3.4 nm
4. 656 nm

Isoelectronic species are

1. CO, CN-, NO+, C22-
2. CO-, CN, NO, C2-
3. CO+, CN+, NO-, C2
4. CO, CN, NO, C2