# What is the best description of exponential decay?

##### 1 Answer

Aug 6, 2014

Exponential decay is when the value or size of something is decreasing over time, but as it gets smaller, it decreases more and more slowly.

Exponential models (both growth and decay) are all about rates of change that are **in proportion** to the value or size of the object in question (e.g. a population, radioactive object, temperature). So in exponential growth, a population may be growing in size - but as the population gets bigger, its growth rate speeds up. Conversely, in an exponential decay situation, as a radioactive object loses mass, its decay rate slows down.