Atom - Origin and Current State - Rare and Theoretical Forms

Rare and Theoretical Forms

While isotopes with atomic numbers higher than lead (82) are known to be radioactive, an "island of stability" has been proposed for some elements with atomic numbers above 103. These superheavy elements may have a nucleus that is relatively stable against radioactive decay. The most likely candidate for a stable superheavy atom, unbihexium, has 126 protons and 184 neutrons.

Each particle of matter has a corresponding antimatter particle with the opposite electrical charge. Thus, the positron is a positively charged antielectron and the antiproton is a negatively charged equivalent of a proton. When a matter and corresponding antimatter particle meet, they annihilate each other. Because of this, along with an imbalance between the number of matter and antimatter particles, the latter are rare in the universe. (The first causes of this imbalance are not yet fully understood, although the baryogenesis theories may offer an explanation.) As a result, no antimatter atoms have been discovered in nature. However, in 1996, antihydrogen, the antimatter counterpart of hydrogen, was synthesized at the CERN laboratory in Geneva.

Other exotic atoms have been created by replacing one of the protons, neutrons or electrons with other particles that have the same charge. For example, an electron can be replaced by a more massive muon, forming a muonic atom. These types of atoms can be used to test the fundamental predictions of physics.

Read more about this topic:  Atom, Origin and Current State

Famous quotes containing the words forms, rare and/or theoretical:

    I would urge that the yeast of education is the idea of excellence, and the idea of excellence comprises as many forms as there are individuals, each of whom develops his own image of excellence. The school must have as one of its principal functions the nurturing of images of excellence.
    Jerome S. Bruner (20th century)

    And this shall be for music when no one else is near,
    The fine song for singing, the rare song to hear!
    That only I remember, that only you admire,
    Of the broad road that stretches and the roadside fire.
    Robert Louis Stevenson (1850–1894)

    There are theoretical reformers at all times, and all the world over, living on anticipation.
    Henry David Thoreau (1817–1862)