The opposite of an acid is a base, and that's exactly what an antacid is. Antacids make you feel better by increasing the pH balance in your stomach. The pH system is a scale for measuring the acidity or alkalinity of a given environment (in this case, your stomach). The scale goes from 0 to 14. A pH of 7 is neutral. Below 7 is acid. Above 7 is alkaline.
Economy is the large set of inter-related economic production and consumption activities which aid in determining how scarce resources are allocated.
A market economy is an economic system in which individuals own most of the resources - land, labor, and capital - and control their use through voluntary decisions made in the marketplace. It is a system in which the government plays a small role. In this type of economy, two forces - self-interest and competition - play a very important role. The role of self interest and competition was described by economist Adam Smith over 200 years ago and still serves as foundational to our understanding of how market economies function.