Sulfur exists in two allotropic forms. Allotropes are forms of an element with different physical and chemical properties. The two forms of sulfur are known as Î±-form and Î²-form (the Greek letters alpha and beta, respectively).
National Organizations American Psychological Association (APA) The American Psychological Association (APA) is located in Washington, D.C., and is the largest scientific and professional organization representing psychology in the United States. APA was founded at the turn of the 20th century, and is the world's largest association of psychologists. APA - Division 16 - Division of School Psychology
The American Board of Professional Psychology was incorporated in 1947 with the support of the American Psychological Association. The ABPP is a unitary governing body of separately incorporated specialty examining boards which assures the establishment, implementation, and maintenance of specialty standards and examinations by its member boards.