# Structure of Atom

## Electronic Configuration Rules | Chemistry Notes

Electronic Configuration: The distribution and arrangement of electrons in various shells, sub-shells and orbitals is called electronic configuration. Electronic configuration follows three rules. Auf Bau Principle: It states: “Electrons occupy shells in increasing order of their energies” or “Electrons occupy sub-shells in increasing order of their energies or n+ℓ values” First electrons fill the sub-shell with …

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## What ate the |Shapes of s, p and d-orbitals

Shapes of Orbitals: Shapes of orbitals are obtained by probability contours. If we plot probability of finding electrons versus distance from nucleus, we see that probability is zero at the nucleus it increases going away from nucleus and becomes maximum at distance “r” and then gradually decreases going further away from nucleus but never becomes …

## Schrodinger Equation

Schrodinger Wave Equation: In 1926, Erwin Schrodinger, a Austrian Physicist, developed an equation, which is given below and is called Schrodinger equation. Where E = total energy of electrons V = potential energy ψ = a wave function (amplitude of wave) ψ2 = probability of finding electron According to Schrodinger electron shows …

## Heisenberg’s Uncertainty Principle – Class 11 Chemistry Notes

Heisenberg’s Uncertainty Principle: In 1927, Warner Heisenberg proposed the uncertainty principle. It states: “It is impossible to state both position as well as momentum of electrons accurately and simultaneously” To determine the position of electron more accurately, radiations of shorter wavelength should be used but according to de Broglie’s equation uncertainty in momentum will increase. …

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## Broglie’s Hypothesis Applications – Dual nature of Radiations

Important Applications of Broglie’s Hypothesis: De Broglie’s hypothesis is good enough to explain Bohr’s postulates. Bohr’s theory states that electron revolves only in orbits of particular radii and in an orbit electron does not emit or absorb energy. It is only possible when electron wave is standing wave and a wave could be standing …

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## Broglie’s Hypothesis: Dual nature of radiations

Louis de Broglie’s Hypothesis: (Dual nature of radiations) There arose a conflict about the nature of radiations. There were two schools of thoughts: (i) wave nature and (ii) particle nature of radiations Both have evidences. So it is difficult to reject any. Louis de Broglie (in 1924) solved this problem by giving …

## Moseley Experiment and Moseley’s Law : Statement and Mathematical Expression

Moseley Experiment : Henry Moseley in 1913 performed an experiment and showed that the frequencies of emitted x-rays increase regularly with the number of positive charges in the nucleus of target elements, used as anode. His experiment became bases to determine atomic numbers. Experimental set up of Moseley’s experiment is shown in figure below. …

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## X-rays: Transitions involving inner-shell electrons

Inner- Shell Transitions and Characteristic X-Rays: Hydrogen atom has only one shell in ground state. Its energy levels are of the order of few electron volts (ev) ; En = – 13.6 ev/n2. Therefore its spectrum has only lines in ultraviolet, visible and infrared region. But other heavy atoms have K, L, M, N…. …

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