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There are additional names used for ions with multiple charges. For example, an ion with a −2 charge is known as a dianion and an ion with a +2 charge is known as a dication. A zwitterion is a neutral molecule with positive and negative charges at different locations within that molecule. [17]
Ionic radius, r ion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice.
A non-fullerene example is [As@Ni 12 As 20] 3−, an ion in which one arsenic (As) atom is trapped in a cage formed by the other 32 atoms. This notation was proposed in 1991 [3] with the discovery of fullerene cages (endohedral fullerenes), which can trap atoms such as La to form, for example, La@C 60 or La@C 82.
Courtesy of Society for Science & the Public. This year's 30 Broadcom MASTERS finalists were announced on Oct. 6. Check out how these pre- and early teens wow-ed the judges with their creativity ...
An atom (or ion) whose oxidation number increases in a redox reaction is said to be oxidized (and is called a reducing agent). It is accomplished by loss of one or more electrons. The atom whose oxidation number decreases gains (receives) one or more electrons and is said to be reduced. This relation can be remembered by the following mnemonics.
Kröger–Vink notation is a set of conventions that are used to describe electric charges and lattice positions of point defect species in crystals. It is primarily used for ionic crystals and is particularly useful for describing various defect reactions. It was proposed by Ferdinand Anne Kröger and Hendrik Jan Vink . [1] [2]
A science fair or engineering fair is an event hosted by a school that offers students the opportunity to experience the practices of science and engineering for themselves. In the United States, the Next Generation Science Standards makes experiencing the practices of science and engineering one of the three pillars of science education.
A science project is an educational activity for students involving experiments or construction of models in one of the science disciplines. Students may present their science project at a science fair, so they may also call it a science fair project. Science projects may be classified into four main types.