Structure Of Atom

Ar contains 18 electrons.
Cl contains 17 electrons.
Na contains 10 electrons.
Ne contains 10 electrons.
Mg contains 12 electrons

For -orbital, to to

For element with Z = 15, electronic configuration is Due to exactly half filled configuration of orbital, the element will have the highest ionization energy.

For -orbital, = 3 and = 1

Power of the bulb =
As only 8% of the energy is emitted as light so, the total energy emitted per second.

Energy of one photon,


Number of photons emitted

{Ne(10 e^-)}\) .
Thus, Na is not isoelectronic with the rest of the species.

For H-like particles,

The number of nodes in a standing wave is equal to the number of points where the wave displacement is zero. The total number of nodes in a wave of quantum number is simply , as each energy level corresponds to an additional node. Therefore, the correct answer is option (C).

In quantum mechanics, the number of nodes in an atomic orbital is given by the formula: where: - is the principal quantum number, - is the azimuthal quantum number. For each orbital: 1. 2s orbital has and , so the number of nodes is: 2. 3s orbital has and , so the number of nodes is: 3. 4s orbital has and , so the number of nodes is: 4. 5s orbital has and , so the number of nodes is: Thus, the minimum number of nodes is in the 2s orbital.

The spectrum of He is similar to that of hydrogen (H) because both are hydrogen-like ions. A hydrogen-like ion is any ion with a single electron orbiting the nucleus, so He (which has one electron) behaves similarly to hydrogen (H) in terms of its energy levels and spectral lines. Therefore, their emission spectra follow the same pattern as both follow the Rydberg formula for hydrogen-like ions.