Around mid-century, Mendeleev began to develop the table of elements which helped in the discovery of new elements. In the last decade of the century, the discovery of radium by Marie and Pierre Curie, and the electron by Becquerel as well as observation of radioactivity in the laboratory, challenged Dalton's theory.
Medications Used to Treat ADHD. Stimulant medications commonly prescribed for attention deficit disorder include methylphenidate (Ritalin, Concerta, Metadate, Methylin) and certain amphetamines (Dexedrine, Dextrostat, Adderall). Methylphenidate is a short acting drug, and in older forms, had to be taken multiple times a day.
Stimulants are the most commonly used type of ADHD medicine. Some medicines are taken more than one time a day, while others are taken only once a day. Your provider will decide which medicine is best. Know the name and dose of each medicine you take.