octet rule

(noun)

A rule stating that atoms lose, gain, or share electrons in order to have a full valence shell of 8 electrons. (Hydrogen is excluded because it can hold a maximum of 2 electrons in its valence shell. )

Related Terms

(noun)

A rule stating that atoms lose, gain, or share electrons in order to have a full valence shell of 8 electrons (has some exceptions).

Related Terms

Examples of octet rule in the following topics:

  • Electron Shells and the Bohr Model

    • This is known as the octet rule which states that, with the exception of the innermost shell, atoms are more stable energetically when they have eight electrons in their valence shell, the outermost electron shell.
    • Theoretically, they would be more energetically stable if they followed the octet rule and had eight.

  • Ions and Ionic Bonds

    • Both ions now satisfy the octet rule and have complete outer shells.
    • In the formation of an ionic compound, metals lose electrons and nonmetals gain electrons to achieve an octet.

  • The Chemical Basis for Life

    • Therefore, carbon atoms can form up to four covalent bonds with other atoms to satisfy the octet rule.

  • Chemical Reactions and Molecules

    • According to the octet rule, elements are most stable when their outermost shell is filled with electrons.

  • Covalent Bonds and Other Bonds and Interactions

    • The octet rule can be satisfied by the sharing of electrons between atoms to form covalent bonds.

  • Rules of Probability for Mendelian Inheritance

    • The rules of probability can be applied to Mendelian crosses to determine the expected phenotypes and genotypes of offspring.
    • The product rule of probability can be applied to this phenomenon of the independent transmission of characteristics.
    • The word "and" is a signal to apply the product rule.
    • The sum rule is applied when considering two mutually-exclusive outcomes that can result from more than one pathway.
    • The word "or" indicates that you should apply the sum rule.

  • Speciation

    • There are exceptions to this rule.
    • Many species are similar enough that hybrid offspring are possible and may often occur in nature, but for the majority of species this rule generally holds.

  • The Punnett Square Approach for a Monohybrid Cross

    • A Punnett square applies the rules of probability to predict the possible outcomes of a monohybrid cross and their expected frequencies.
    • A Punnett square, devised by the British geneticist Reginald Punnett, can be drawn that applies the rules of probability to predict the possible outcomes of a genetic cross or mating and their expected frequencies.To prepare a Punnett square, all possible combinations of the parental alleles are listed along the top (for one parent) and side (for the other parent) of a grid, representing their meiotic segregation into haploid gametes .
    • Furthermore, because the YY and Yy offspring have yellow seeds and are phenotypically identical, applying the sum rule of probability, we expect the offspring to exhibit a phenotypic ratio of 3 yellow:1 green.

  • Nonrandom Mating and Environmental Variance

    • Bergmann's Rule is an ecologic principle which states that as latitude increases the body mass of a particular species increases.
    • The data are taken from a Swedish study investigating the size of moose as latitude increases as shows the positive relationship between the two, supporting Bergmann's Rule.

  • Discovery of DNA

    • Chargaff's Rule showed that in natural DNA, the number of guanine units equals the number of cytosine units and the number of adenine units equals the number of thymine units.