<span>Geologists generally know the age of a rock by determining the age of the group of rocks, or formation, that it is found in. The age of formations is marked on a geologic calendar known as the geologic time scale. Development of the geologic time scale and dating of formations and rocks relies upon two fundamentally different ways of telling time: relative and absolute.</span>
The part of the experiment in which the experimental factor has been removed is referred to as <span>the independent variable. </span>The dependent variable<span> is the element which is being measured in an experiment or evaluated in a mathematical equation.</span>
A salmon can live out of water for 2 hours
