But, as the saying goes, rules are made to be broken. And the byte rule has more elements that break the rule than following it. When elements in the second series search for bytes per covalent bond, they maximize their main shell capacity (the second energy level) to eight valence electrons, just as predicted by the byte rule. For example, carbon can form four bonds with hydrogen atoms to make methane, nitrogen can form three bonds with hydrogen to form ammonia, oxygen makes two bonds with hydrogen in water, and fluorine can form hydrofluoric acid by binding to a single hydrogen. Neon, of course, is content with eight valence electrons already in its valence shell. In 1864, the English chemist John Newlands classified the sixty-two known elements into eight groups based on their physical properties. [4] [5] [6] [7] At the end of the 19th century, the In the nineteenth century, it was known that coordination compounds (formerly called “molecular compounds”) were formed by the combination of atoms or molecules in such a way that the valences of the atoms involved were apparently filled. In 1893, Alfred Werner showed that the number of atoms or groups associated with a central atom (the “coordination number”) is often 4 or 6; Other coordination numbers up to a maximum of 8 were known, but less frequent. [8] In 1904, Richard Abegg was one of the first to extend the concept of coordination number to a concept of valence, in which he distinguished atoms as electron donors or acceptors, resulting in positive and negative valence states that closely resemble the modern concept of oxidation states. Abegg found that the difference between the maximum positive and negative valences of an element under his model is often eight. [9] Gilbert N. Lewis called this discovery Abegg`s rule in 1916 and used it to formulate his cubic atomic model and the “rule of eight,” which began to distinguish between valence and valence electrons.
In 1919, Irving Langmuir refined these concepts by renaming them “cubic byte atom” and “octet theory”. [11] “Byte theory” evolved into what is now known as the “byte rule.” Sulfur hexafluoride is a very stable gas and a good electrical insulator that is sometimes used in electronics. But take a closer look – six covalently bonded fluorine atoms mean twelve electrons are involved in sulfur bonds! The last time I checked twelve, there were more than eight. This would make the sulfur in SF6 “hypervalent”. In methane (CH4), there are two different atoms to consider. We start with carbon, which has four covalent bonds. There are two electrons associated with each covalent bond, so carbon follows the octet rule. But the remaining elements of block p aren`t as cooperative, which sparked a heated debate between these two fathers of the byte rule — a debate that continues to this day. Let us take the example of sulphur. When combined with hydrogen, it gives dihydrogen sulfide, which is perfectly analogous to water, which is dihydrogen oxide.
Problem: Using what you know about the byte rule, draw the structure for HCN The same idea would apply to sulfur (S), another element in column 6. However, there are notable exceptions to the byte rule, such as sulfur`s ability to form 6 bonds (not shown here). The quantum theory of the atom explains the eight electrons as a closed shell with an electronic configuration s2p6. A closed-shell configuration is one in which low energy levels are full and higher energy levels are empty. For example, the ground state of the neon atom has a complete shell n = 2 (2s2 2p6) and an empty shell n = 3. According to the byte rule, atoms immediately before and after neon in the periodic table (i.e. C, N, O, F, Na, Mg, and Al) tend to reach a similar configuration by gaining, losing, or sharing electrons. Many reactive intermediates are unstable and do not obey the byte rule.
These include species such as carbenes, as well as free radicals and the methyl radical (CH3), which has an unpaired electron in a non-binding orbital on the carbon atom and no electrons with an opposite spin in the same orbital. Another example is radical chlorine monoxide (ClO•), which is involved in ozone depletion. These molecules often react to complete their byte. Electron-poor molecules such as boranes also do not obey the byte rule, but share delocalized electrons similar to metal bonds. The byte rule is a term in chemistry. It allows us to determine the atomic structure of most chemicals. The byte rule is also used to determine the names and formulas of many chemicals. Lewis argued that additional covalent bonds might be possible if energy-close d orbitals were recruited to form additional bonds. Does sulfur in SF6 really violate the byte rule? Is it the involvement of the d orbit or simply the larger size of the sulfur atom that is responsible for this behavior? Believe it or not, a century later, the answer to this question is not completely resolved.