Explain why scientists use the metric system for scientific measurements.

To obtain and maintain the reliability of the data gathered. Reliability is known as measuring a tool over and over again and it still yielded the same results. Like a ruler with only eleven inches. As long as that ruler will be used to measure to all the lengths of an object, then it is reliable. For validity, that is the tool measures what it is made to measure. So when the tool used for measuring length indeed measures length, then it is valid.