S-orbital cannot accommodate more than two electrons because if three electrons are added in S-orbital then the value of four quantum number for two electrons will be same, which is against the Pauli's exclusion principle.

When electrons are infinite separation from the nucleus then no electrostatic force exists and the energy of electron is zero. When the electrons brought towards the nucleus then the energy is expense to do work and energy is decreased. Therefore, the energy of electrons in shell is negative.

The most striking features of atomic spectra (spectrum of only atom but no molecules) is that the emitted radiation has very sharp, discrete wavelengths. These atomic spectra are, therefore, called line spectra.

Bohr's theory of the atom was proposed in the early 20th century and was based on the idea that electrons move in fixed orbits around the nucleus. According to this theory, the position and momentum of an electron in an atom can be determined with absolute precision at any given moment, which seems to contradict Heisenberg's uncertainty principle.

Heisenberg's uncertainty principle states that it is impossible to determine the exact position and momentum of a particle simultaneously. This...

The de-Brogile equation refers a moving particle's wavelength with its momentum. The Brogile wavelength is the wavelength, , associated with a moving particle and is relevant to its momentum, p, through the Planck constant, h. In other words, you can say that matter behaves like waves.

= h/p

The electronic configuration of
i. CU₂₉ = 1s², 2s² 2p⁶, 3s² 3p⁶, 4s¹ 3d¹⁰
ii. K₁₉ = 1s², 2s² 2p⁶, 3s² 3p⁶, 4s¹

Heisenberg uncertainty principle goes against the concept of Bohr's atomic model.

It states that it is impossible to determine the exact position as well as momentum of a microscopic moving particle.

The electron whose valence shell electronic configuration 4s² may be Calcium(Ca). The atomic number of calcium is 20. The electronic configuration of calcium is

Ca₂₀ = 1s², 2s² 2p⁶, 3s² 3p⁶, 4s²

The total number of p-electrons are 12.

Magnetic quantum number represents the orientation of orbital in three dimensional spaces i.e. the number of orbital that are present for a particular value of principle quantum number.

Magnetic quantum number specifies the orientation of an orbital.

For 3^rd orbital,

The value of principle quantum number (n) = 3
The value of azimuthal quantum number (l) = 0 to (n-1) = 0, 1, 2

In an orbit, the angular momentum is always quantized. Quantization means that a quantity can vary only discontinuously to get a specific value i.e. the orbits are possible only after a certain separation and they are not possible continuously.

Azimuthal quantum number (l) specifies the shape of orbital.

Quantum number: The atomic parameter which is used to describe the position and energy of an electron in an atom is called Quantum number.

In the case of filing of electrons into orbital having equal energies, called degenerate orbital. It states that "Electrons will distribute themselves in degenerate orbitals so as to give maximum multiply as much as possible."

The limitations of Bohr's theory are:

i. A single line of hydrogen spectrum is found to be composed of severally closed packed. The origin of these lines of hydrogen spectra is not explained by Bohr.

ii. It fails to explain the splitting of spectral lines into very fine lines under magnetic field and eternal electric field.

The principle quantum number, is represented by "n" where "n" represents the most probable distance of an electron from the nucleus.If n = 1 then it means the electron is in the first shell but if it gains electron and jumps to another shell then the value of n increases -farther is the electron from the nucleus, higher will be the energy stored in the electron and neareris it to the nucleus, lower will be it's energy. So we can say that Principal Quantum numbers specifies the energy of an...

When enegy is supplied to any atom, the electrons in it gain enegy and jump to a new shell, matching exactly the separation between the energies of the given orbits. We,see these photons as lines of coloured light (the Balmer Series, for example) in emission or dark lines in absorption.When we take a large number of hydrogen atoms then the energy level of different electrons can be seen.

During theα-scattering experiment conducted by Rutherford, only very few, almost 1 in 20,000-100,000 particles bounced back.

Hence, we can conclude from this that, the atom has positively charged particles that deflected the +veα-particles, but that positive charge is concentrated in a very very small area compared to the atom itself, such that, it completely deflects the very few particles.

The are main postulates ofDalton’s atomic theory are:

1. All matters are composed of extremely small, and discrete particles called atoms.

2. Atom is indestructible/ indivisible and do not undergo any division during a chemical reaction.
(principle of indestructability of matter)

3. Atoms of same elements are always identical in shape, size and mass and differ from atoms of other elements in the same.

4. Atoms always combine in simple whole number ratio to form a molecule (then called as compound...

a. Hund’srule of maximum multiplicity

Hund proposed a rule of filling of de-generate orbitals (having equivalent energy) with electrons known as Hund's rule of maximum multiplicity.

It states:
In the orbitals of same sub-energy level (sub-orbitals), electrons are filled single first (in the same spin) before filling up fully in pair.
The electrons prefer to occupy separate orbitals rather than getting paired in the same orbital.

b. Pauli's Exclusion principle:

Pauli put forward a principle that...

These models of atom are based on the wave theory and quantum theory respectively.

The quantum mechanical modeldescribes the probable location of electrons in atoms by describing: Principal energy level, energy sublevel, orbital(in each sub-level), spin.

Wave mechanical model isa theory, which states that the electrons have dual nature and are similar to the wave of energy as well as particles. It is also known as quantum mechanical theory.