Structure of Atom · Question 14

When electromagnetic radiation of wavelength 300 nm falls on the surface of a metal, electrons are emitted with the kinetic energy of 1.68 105 J mol-1. What is the minimum energy needed to remove an electron from the metal? (h = 6.626 10-34 J s, c = 3 108 m s-1, NA = 6.022 1023 mol-1)

1. 2.31 105 J mol-1
2. 2.31 106 J mol-1
3. 3.84 104 J mol-1
4. 3.84 10-19 J mol-1

A particular station of All India Radio, New Delhi broadcasts on a frequency of 1,368 kHz (kilohertz). The wavelength of the electromagnetic radiation emitted by the transmitter is : [speed of light c = 3.0 108 m s-1]

1. 21.92 cm
2. 219.3 m
3. 219.2 m
4. 2192 m

From the following pairs of ions which one is not an iso-electronic pair?

1. Fe2+, Mn2+
2. O2-, F-
3. Na+, Mg2+
4. Mn2+, Fe3+

The number of protons, neutrons and electrons in 175 71Lu, respectively, are :

1. 104, 71 and 71
2. 71, 71 and 104
3. 175, 104 and 71
4. 71, 104 and 71

4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is :

1. 6p > 5f > 4d > 5p
2. 5f > 6p > 4d > 5p
3. 5f > 6p > 5p > 4d
4. 6p > 5f > 5p > 4d

Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?

1. Paschen series
2. Brackett series
3. Lyman series
4. Balmer series

Which one is a wrong statement?

1. Total orbital angular momentum of electron in s-orbital is equal to zero.
2. An orbital is designated by three quantum numbers while an electron in an atom is designated by four quantum numbers
3. The electronic configuration of N atom is [figure]
4. The value of m for dz2 is zero.

Which one is the wrong statement ?

1. The uncertainty principle is E t h4
2. Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.
3. The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.
4. de-Broglie's wavelength is given by = hmv, where m = mass of the particle, v = group velocity of the particle.

Two electrons occupying the same orbital are distinguished by

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

How many electrons can fit in the orbital for which n = 3 and l = 1?

1. 2
2. 6
3. 10
4. 14