How many electrons will be present in the highest principal energy level of cobalt (z = 27) ?
2
7
9
1
What is the number of electrons in an atom which have n = 4, l = 2, m = -1 ?
10
5
What is the time taken for an electron to complete an revolution in the Bohr orbit of hydrogen atom ?
4π2mr2/nh
h/2πmr
nh.4π2mr
2πmr/n2h2
The observation that the ground state of nitrogen atom has 3 unpaired electrons in its electronic configuration is associated with
Heisenberg's uncertainty principle
Pauli's exclusion principle
Aufbau principle
Hund's rule of maximum multiplicity
When alpha particles are passed through a thin metal foil, most of them go straight through the foil because
Alpha particles are positively charged
Alpha particles are much heavier than electron.
Most part of the atom is empty.
Alpha particles move with high velocity
The spectral line obtained when an electron jumps from n = b to n = 4 energy level belongs to
Paschen series
Brackett series
Lyman series
none of these
What is the wave length of a radio wave having frequency 2.5 × 105 Hz ?
1.2 × 103m
1.2 × 10-3m
8.33 × 102m
None of these
The maximum number of electrons in a subshell having the same value of spin quantum number is given by
l (l + 1)
√l(l + 1)
l + 2
2l + 1
126 C and 146 C differ from each other in the number of
Nucleons
Mesons
Electrons
Protons
The ground state of an atom means that all the electrons are
Having the same energy
In the lowest possible energy state
In the first orbit
In the nucleus
