Matter & Energy


Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Ununbium

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Element 112, also called ununbium (Uub), chemical element with atomic number 112., is produced artificially by nuclear fusion (in which an element with larger atoms is produced by fusing together smaller atoms from other elements). Each ununbium atom has a very large nucleus, or central mass, containing positively charged particles called protons and neutral particles called neutrons. The large number of particles in the nucleus makes the atom unstable and causes the atom to split apart into smaller components soon after it is created. Scientists gave ununbium its temporary name according to a system that uses Latin prefixes for the atomic number (un = 1, un = 1, bi = 2), followed by the suffix -ium or -um. The element will eventually be given a more conventional permanent name by its discoverers. Ununbium was first discovered in 1996 by scientists at the Heavy-Ion Research Laboratory in Darmstadt, Germany.

Ununbium has the atomic number 112, which means that each Uub atom contains 112 protons in the nucleus. Scientists at the Heavy-Ion Research Laboratory created an atom of ununbium that contained 165 neutrons, labeled ununbium-277 (112 protons + 165 neutrons = ununbium-277).

Ununbium was created by nuclear fusion of the smaller elements lead (Pb) and zinc (Zn). Because the ununbium nucleus contains so many particles, ununbium is unstable and undergoes spontaneous fission, a process in which the atom breaks into smaller “daughter” components. When the atom splits, it releases energy in the form of electromagnetic waves and electrically charged bits of matter. This energy is known as radiation (see Radioactivity). Ununbium-277 has a very brief life span of .00048 seconds. By 1998 ununbium-277 was the only confirmed isotope of Element 112. Other isotopes of element 112 would be forms of the element with the same number of protons in the nucleus, but a different number of neutrons.

Ununbium belongs to Group 12 (IIb) on the periodic table, which also contains the naturally occurring elements zinc (Zn), cadmium (Cd), and mercury (Hg) (see Chemical Element). Relative to other metallic elements, zinc, cadmium, and mercury have high boiling points and low melting points. Zinc, cadmium, and mercury are all reactive with oxygen (O), sulfur (S), and the halogens (Group 17 or VIIa). Because elements in the same group, or column, on the periodic table often share similar properties (a pattern known as the periodic law), scientists expect ununbium to share properties with other Group 12 elements. However, because of the very limited amount of ununbium that has been produced and its extremely short life span, scientists have been unable to determine chemical properties of this unstable element.