Structure of Atom

The Bohr radius of a hydrogen like species is 70.53 pm. The species and the stationary state (n) are respectively (Given : Hydrogen atom Bohr radius is 52.9 pm)

1. Li2+, 3
2. He+, 3
3. He+, 2
4. Li2+, 2

The species having identical radii according to the Bohr's theory are : Choose the correct answer from the options given below :

1. A and C Only
2. A and E Only
3. B and E Only
4. C and D Only

What is the energy (in J atom-1) required for the following process ? Li2+(g) Li3+(g) + e- (Take the ionization energy for the H atom in the ground state as 2.18 10-18 J atom-1)

1. 8.72 10-18
2. 1.962 10-18
3. 1.962 10-17
4. 6.54 10-17

Which of the following statements regarding the energy of the stationary state is true in the following one-electron systems ?

1. +2.18 10-18 J for second orbit of He+ ion
2. +8.72 10-18 J for first orbit of He+ ion
3. -1.09 10-18 J for second orbit of H atom.
4. -2.18 10-18 J for third orbit of Li2+ ion

The energy required by electrons, present in the first Bohr orbit of hydrogen atom to be excited to second Bohr orbit is J mol-1. Given: RH = 2.18 10-11 ergs.

1. 9.835 1012
2. 1.635 10-11
3. 1.635 10-18
4. 9.835 105

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?

1. The electron in a H atom's stationary state moves in a circle around the nucleus.
2. An atom can take only certain distinct energies E1, E2, E3, etc. These allowed states of constant energy are called the stationary states of atom.
3. An atom in a stationary state does not emit electromagnetic radiation as long as it stays in the same state.
4. When an electron makes a transition from a higher energy stationary state to a lower energy stationary state, then it emits a photon of light.

According to Bohr's model of hydrogen atom, which of the following statement is incorrect?

1. Radius of 4th orbit is four times larger than that of 2nd orbit
2. Radius of 8th orbit is four times larger than that of 4th orbit
3. Radius of 6th orbit is three times larger than that of 4th orbit
4. Radius of 3rd orbit is nine times larger than that of 1st orbit