Lewis Acid-Base Concept. The Lewis theory classifies a substance as an acid if it acts as an electron-pair acceptor and as a base if it acts as an electron-pair donor. Other ways of classifying substances as acids or bases are the Arrhenius concept and the Bronsted-Lowry concept.ewis Acid-Base Concept. The Lewis theory classifies a substance as an acid if it acts as an electron-pair acceptor and as a base if it acts as an electron-pair donor. Other ways of classifying substances as acids or bases are the Arrhenius concept and the Bronsted-Lowry concept.
Microsoft Excel was created by Microsoft Corporation. It was first released in 1985.
Excel was developed first and foremost as a tool to make creating tables of figures and calculations easier and quicker. Key to this end is the grid design of the main work space in Excel. However, this same feature can make formatting labels, titles, non-numeric data, and explanatory paragraphs problematic. This guide aims to help you overcome these problems.