An electron is a subatomic particle that carries a negative electric charge. It has no known substructure and is believed to be a point particle. An electron has a mass that is approximately 1/1836 that of the proton. The intrinsic angular momentum (spin) of the electron is a half integer value of ¹<big>⁄</big>₂, which means that it is a fermion. Electrons, which belong to the first generation of the lepton particle family, participate in gravitational, electromagnetic and weak interactions. Electrons have quantum mechanical properties of both a particle and a wave, so they can collide with other particles and be diffracted like light. Since an electron is a fermion, no two electrons can occupy the same quantum state, a property known as the Pauli exclusion principle. The electron was identified as a particle in 1897 by J. J. Thomson and his team of British physicists. In many physical phenomena, such as electricity, magnetism, and thermal conductivity, electrons play an essential role. An electron generates a magnetic field while moving, and it is deflected by external magnetic fields. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding.

Read the rest of this article: http://en.wikipedia.org/wiki/Electron

_______________________________ Today's selected anniversaries:

1783:

The first successful untethered flight by humans in a hot air balloon was made by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in Paris. http://en.wikipedia.org/wiki/History_of_ballooning%23First_manned_flight

1920:

Irish War of Independence: On Bloody Sunday in Dublin, the Irish Republican Army killed more than a dozen British intelligence officers known as the Cairo Gang, and the Auxiliaries of the Royal Irish Constabulary opened fire on players and spectators at a Gaelic football match in Croke Park. http://en.wikipedia.org/wiki/Bloody_Sunday_%281920%29

1964:

The Verrazano-Narrows Bridge , a suspension bridge connecting Staten Island and Brooklyn in New York City at the Narrows, opened to traffic, becoming the largest suspension bridge in the world at the time. http://en.wikipedia.org/wiki/Verrazano-Narrows_Bridge

1974:

Explosives placed in two central pubs in Birmingham, England, killed 21 people and injured 182 others, and eventually led to the arrest and imprisonment of six people that became known as the Birmingham Six. http://en.wikipedia.org/wiki/Birmingham_pub_bombings

1977:

"God Defend New Zealand" became New Zealand's second national anthem, on equal standing with "God Save the Queen", which had been the traditional one since 1840. http://en.wikipedia.org/wiki/God_Defend_New_Zealand

_____________________________ Wiktionary's word of the day:

plicate (adj): Folded lengthwise, especially in multiple in parallel sections; corrugated http://en.wiktionary.org/wiki/plicate

___________________________ Wikiquote quote of the day:

If your object is to secure liberty, you must learn to do without authority and compulsion. If you intend to live in peace and harmony with your fellow-men, you and they should cultivate brotherhood and respect for each other. If you want to work together with them for your mutual benefit, you must practice cooperation. The social revolution means much more than the reorganization of conditions only: it means the establishment of new human values and social relationships, a changed attitude of man to man, as of one free and independent to his equal; it means a different spirit in individual and collective life, and that spirit cannot be born overnight. It is a spirit to be cultivated, to be nurtured and reared, as the most delicate flower it is, for indeed it is the flower of a new and beautiful existence. --Alexander Berkman http://en.wikiquote.org/wiki/Alexander_Berkman