Tips & Tricks for Atomic Structure & Theory

Tips & Tricks for Atomic Structure & Theory

* All lines in the visible region are of Balmer series but reverse is not true i.e., all Balmer lines will not fall in visible region.

* A part of an atom up to penultimate shell is a kernel or atomic core.

* If the energy supplied to hydrogen atom is less than 13.6 eV it will awpt or absorb only those quanta which can take it to a certain higher energy level i.e., all those photons having energy less than or more than a particular energy level will not be absorbed by hydrogen atom, but if energy supplied to hydrogen atom is more than 13.6eV then all photons are absorbed and excess energy appear as kinetic energy of emitted photo electron.

* No of nodes in any orbital = (n-l-1)

* No of nodal planes in an orbitals = l

* The d orbital which does not have four lobes is dz2

* The d orbital whose lobes lie along the axis is dx2-y2

* Spin angular momentum = √s(s+1)(h/2π)

* Total spin = +  (n/2); where n is no of unpaired e-

* Magnetic moment = √n(n+1) B.M.  (Bohr magnetron) of n unpaired e-

* Ion with unpaired electron in d or f orbital will be coloured.

* Exception of E.C. are Cr(24), Cu(29), Mo(42), Ag,(47),W(74), Au(79)

* No. of waves n = (2πr)/λ (where λ=h/mv)

* No. of revolutions of e- per second is v/2πr

* The solution of schrodinger wave equation gives principal, azimuthal and magnetic quantum numbers but not the spin quantum number.

* In the Rydberg formula, when n2 = ∞ the line produced is called the limiting line of that series.

* Among various forms of visible light, violet colour has shortest

* wavelength, highest frequency and highest energy.

* Red coloured light has largest wavelength, least frequency and lowest energy in visible light.

* Elements give line spectra. The line spectrum is characteristic of the excited atom producing it. No two elements have identical line spectrum.

* The line spectrum results from the emission of radiations from the atoms of the elements and is therefore called as atomic spectrum.

* Atoms give line spectra (known as atomic spectrum) and the molecules give band spectra (known as molecular spectrum).

* The negative potential at which the photoelectric current becomes zero is called cut off potential or stopping potential.

* When energy or frequency of scattered ray is lesser than the incident ray, it is known as Compton effect.

* The instrument used to record solar spectrum is called spectrometer or spectrograph developed by Bunsen and Kirchoff in 1859.

* The intensities of spectral lines decreases with increase in the value of n. For example, the intensity of first Lyman line (2→1) is greater than second line (3→)and so on.

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