edward frankland (1825 1899). group 5a elements when the formulae of inorganic chemical compounds...
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Edward Frankland (1825 1899)
Group 5A Elements
When the formulae of inorganic chemical compounds are considered, even a superficial observer is impressed with the general symmetry of their construction. The compounds of nitrogen, phosphorus, antimony, and arsenic, especially, exhibit the tendency of these elements to form compounds containing 3 or 5 atoms of other elements; and it is in these proportions that their affinities are best satisfied: thus in the ternal group we have: NO3, NH3, NI3, NS3, PO3, PH3, PCl3, SbO3, SbH3, SbCl3, AsO3, AsH3, AsCl3, etc.: and in the five-atom group, NO5, NH4O, NH4I, PO5, PH4I, etc. Without offering any hypothesis regarding the cause of this symmetrical grouping of atoms, it is sufficiently evident from the examples just given, that such a tendency or law prevails, and that, no matter what the character of the uniting atoms may be, the combining power of the attracting element, if I may be allowed the term, is always satisfied by the same number of these atoms.
Phil. Trans. Royal Soc.1852
Richard Abegg (1869 -1910)
Abegg’s RuleThe difference between the maximum positive and negative valence of an element is frequently eight.
Nature of LightIsaac Newton (1643- 1727) Christiaan Huygens (1629 – 1695)
Properties of Waves
Reflection Refraction
Diffraction
Interference
Properties of Light
Reflection Refraction
Reflection of Light Corpuscles Refraction of Light Corpuscles
Huygen Construction for Reflection
Huygen Construction for Refraction
Huygen’s Construction
Young’s Double Slit ExperimentThomas Young (1773 – 1829)
Laser Source for Double Slit Experiment
Interpretation of the Double Slit Results
Fresnel’s DotAugustin Jean Fresnel (1788 – 1827)
Simeon Poisson (1781 – 1840)
Maxwell’s EquationsJames Clerk Maxwell (1831 – 1879)
Electromagnetic Radiation
Heinrich Hertz (1857 – 1894)
Light is a Wave
Blackbody Radiation
Cavities as Blackbodies
http://mediaserve.nmt.edu/portal/app/EODILecturePortal.html
http://breeze.nmt.edu/st589dchemnatblackbody/
The Ultraviolet Catastrophe
Lord Rayleigh James Jeans
After a few weeks of the most strenuouslabor of my life, the darkness lifted anda new, unimagined prospect began to dawn.
Max Planck (1858 – 1947)
Photoelectric Effect
Albert Einstein (1879 – 1955) Robert Millikan (1868 - 1953)
Einstein’s equation was a bold prediction,for at that time there was no evidence thatPlanck’s constant had any applicability outside of blackbody radiation and therewere no experimental data on the [kineticenergy] as a function of frequency. Physics by Paul A. Tipler
Millikan’s Photoelectric Data
The Double Slit Experiment Revisited
Light is a Particle