Thus by 1803 there were two known rare earth elements, yttrium and cerium, although it took another 30 years for researchers to determine that other elements were contained in the two ores ceria and yttria (the similarity of the rare earth metals' chemical properties made their separation difficult).
For instance, students who pursue a Ph.D. in psychology usually take from five to seven years depending upon required coursework as well as internship and supervised residency requirements.
Updated June 14, 2016. A doctorate-level degree in psychology is required to work in many job areas, including as a licensed clinical psychologist or counseling psychologist. A doctorate degree is also often required in fields such as school psychology or health psychology. So how long does it take to get a Ph.D. in Psychology? First, it is important to realize that the degree requirements can vary depending upon the field that you decide to pursue. A Ph.D., or Doctor of Philosophy, degree is not necessarily your only option. In some cases, you might want to also consider the PsyD (Doctor of Psychology) or the EdD (Doctor of Education) degree options.