The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li2+ ion (atomic number = 3) in a similar state is :
0.176 Å
0.30 Å
0.53 Å
1.23 Å
A.
0.176 Å
Given, r0 = radius of H atom in ground state = 0.5 Å
n = number of orbit = 1
Z = Atomic number of Li = 3
= 0.176 Å
The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 × 107 m-1)
91 nm
192 nm
406 nm
9.1 × 10-8 nm
The radioactive isotope which is used in the treatment of cancer can be made by (n, p) reaction. For this reaction the target nucleus is
The energy of second Bohr orbit of the hydrogen atom is -328 kJ mol-1; hence the energy of fourth Bohr orbit would be
-41 kJ mol-1
-1312 kJ mol-1
-164 kJ mol-1
-82 kJ mol-1
If the energy difference between the ground state of an atom and its excited state is 4.4× 10-4J, the wavelength of photon required to produce the transition :
2.26 × 10-12m
1.13 × 10-12m
4.52× 10-16m
4.52 × 10-12m
Splitting of spectrum lines in magnetic field is
Stark effect
Raman effect
Zeeman effect
Rutherford effect
Decrease in atomic number is not observed during
β- emission
α- emission
positron emission
electron capture
According to Bohr's theory, the angular momentum for an electron in 5th orbit is
2.5 h/
5 h/
25 h/
5 / 2h
If a species has 16 protons, 18 electrons and 16 neutrons, the symbol (with charge) of species is
S-
Si2-
P3-
S2-
'No two electrons in an atom can have the same set of quantum numbers.' This principle is known by which one of the following?
Zeeman's exclusion principle
Stark's exclusion principle
Pauli's exclusion principle
Hersbach's exclusion principle