Structure Of Atom

Electron density of orbital in plane is zero.

and
set represents that the last electron enters in a orbital.
Among the given options, only is the element, last electron of which enters in a orbital.

Let the velocity of the particle
Wavelength of the particle
or
de-Broglie relationship is

or

In photoelectric effect, photoelectrons are emitted only when light of frequency higher than the threshold frequency falls at the surface of the metal. The excess energy (excess to that of threshold energy) gives the kinetic energy to the electron. Thus, kinetic energy of photoelectron increases linearly with the frequency of incident light.

Number of spectral lines obtained when an electron drops from level to ground level
Number of emission lines obtained, when electron drops from level to ground state

Louis de-Broglie proposed that matter has wave like as well as particle like characteristics. Indeed, he proposed the dual nature of matter.

Bohr's model of hydrogen atom was unable to explain Heisenberg' s uncertainty principle.

As per uncertainty principle It is impossible to determine the position and momentum of a moving electrons in an atoms with accuracy or certainty.

,
Orbital =
No of electrons

According to de-Broglie equation

Answer (a) electrons

According to Plank's, atoms and molecules could emit or absorb energy in discrete quantities only, which are called quantum.

Energy of photon,
Energy of mole of photon,

Atoms with identical atomic number but different atomic mass number are called isotopes, e.g.
and
are three isotopes of hydrogen.

For