Allylic and benzylic cations have delocalized electrons, so they are more stable than similarly substituted carbocations with localized electrons. An allylic cation is a carbocation with the positive charge on an allylic carbon; an allylic carbon is a carbon adjacent to an sp2 carbon of an alkene. A benzylic cation is a carbocation with the positive charge on a benzylic carbon; a benzylic carbon is a carbon adjacent to an sp2 carbon of a benzene ring. The allyl cation is an unsubstituted allylic cation, and the benzyl cation is an unsubstituted benzylic cation.
Numeracy is the ability to reason and to apply simple numerical concepts. Basic numeracy skills consist of comprehending fundamental arithmetics like addition, subtraction, multiplication, and division.he first couple of years of childhood are considered to be a vital part of life for the development of numeracy and literacy. There are many components that play key roles in the development of numeracy at a young age, such as Socioeconomic Status (SES), parenting, Home Learning Environment (HLE), and age.
A numerical or continuous variable (attribute) is one that may take on any value within a finite or infinite interval (e.g., height, weight, temperature, blood glucose, ...). There are two types of numerical variables, interval and ratio. An interval variable has values whose differences are interpretable, but it does not have a true zero.