Structure of Atom · Question 24

Which of the following pairs of d-orbitals will have electron density along the axes ?

1. dz2, dxz
2. dxz, dyz
3. dz2, dx2-y2
4. dxy, dx2-y2

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium ? (At. no. Z = 22)

1. 4s 3s 3p 3d
2. 3s 3p 3d 4s
3. 3s 3p 4s 3d
4. 3s 4s 3p 3d

The number of d-electrons in Fe2+ (Z = 26) is not equal to the number of electrons in which one of the following ?

1. d-electrons in Fe (Z = 26)
2. p-electrons in Ne (Z = 10)
3. s-electrons in Mg (Z = 12)
4. p-electrons in Cl (Z = 17)

The angular momentum of electron in 'd' orbital is equal to

1. 2 3
2. 0
3. 6
4. 2

What is the maximum number of orbitals that can be identified with the following quantum numbers? n = 3, l = 1, ml = 0

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

Calculate the energy in joule corresponding to light of wavelength 45 nm. (Planck's constant, h = 6.63 10-34 J s, speed of light, c = 3 108 m s-1)

1. 6.67 1015
2. 6.67 1011
3. 4.42 10-15
4. 4.42 10-18

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