Lewis structure acids and bases

[Shaniya Kerns 4D]

How do we determine whether a structure is a lewis base or a lewis acid? Are there any indicators that can tell us right away or do we have to go through a process of examination?

[805909756]

If there is a lone pair on the molecule it is a Lewis base because it can donate this extra electron to a Lewis base. Typically, elements from Groups 1 and 2 (alkali and alkaline earth metals) are good Lewis bases. Also, elements with lone pairs, such as nitrogen, oxygen, and halogens, can act as Lewis bases. Lewis acids have an electron-deficient site, such as an atom with an incomplete octet or a positively charged ion. Transition metals, metal cations, and species with a positive charge are often Lewis acids. Also, elements like boron, which can accommodate additional electrons, are Lewis acids. Species with electron-deficient regions or incomplete octets are more likely to act as Lewis acids.