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.
A PsyD degree is a Doctor of Psychology degree. It is a doctoral degree and it is the highest degree a psychology student can earn. Equivalent to the PhD in Psychology, the PsyD focuses more on practical skills than on research and prepares students for a future in clinical psychology.he answer to this question depends greatly on the school and on the particular program. A Masterâs degree takes around two years to complete. A PhD, including the PsyD degree, takes anywhere between four and six years to complete, which means a good two to four years more than a Masterâs degree.