Word: electron
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Dates: during 1960-1969
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...linear accelerator to bombard a tiny amount of einsteinium (a transuranium element discovered in 1952) with alpha particles which consist of two protons and two neutrons. "We expected the alpha particles to join with the heavier isotope of einsteinium," says Hulet, "and then decay by a process called 'electron capture' to fermium...
...stress, a solid-state chemical reaction is triggered that blunts small cracks just as they begin, then fills them in to prevent major wounds. The chemical change precipitating this "self-healing" process takes place on a near-atomic scale, and can be observed only with the aid of an electron microscope. The actual halting and filling in of a crack, however, can sometimes be seen with the naked...
Enlarging the Evidence. Walker's most proven technique is based on the fact that most rocks and minerals contain a small impurity of uranium, which fissions (splits), leaving tiny scars or tracks inside the substance. Until recently, this phenomenon remained unobserved. Walker found that even with an electron microscope the fossil tracks were too tiny-.001 of an inch long and only ten atoms wide-to see in significant numbers...
...Electron microscopists have since photographed lysosomes, and Dr. de Duve, now at Rockefeller University, has figured out some of the ways they work (see diagram). In a typical case, a foreign particle (it may be a virus, a bacterium or a chemical) reaches the side of a cell and is sucked in, sealed off by a piece of the cell's own membrane. Standing by inside the cell is a lysosome, packed with enzymes. Lysosome and invader, now packaged in a phagosome, are drawn together and fuse. In the resulting sac, called a vacuole, the foreign substance is digested...
Mass into Energy. Gell-Mann's quark is an unusual creature indeed. Unlike other known particles, which are electrically neutral or have positive or negative charges that are whole multiples of the basic charge of the electron, quarks would have a charge of either one-third or two-thirds of the unit electron charge. Arranged in different combinations, quarks would form practically any one of the confusing variety of subatomic particles...