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.
Generally, it will take you about one to one and a half years less time to earn your Psy.D. compared to a Ph.D. For your Ed.D. degree, you will need 3-5 years to complete it. It is important to remember that many applicants to Ed.D. degree programs already have a masterâs degree in a related speciality.Most applicants to Ph.D. and Psy.D. programs start their programs with only a bachelorâs degree.o earn your Ph.D. in psychology, you will need 5-7 years to earn the degree. You will need to finish all of the required classes and you also will have to do an internship or residency of some sort. A Ph.D. program usually ends with a detailed and long dissertation.