Prescription painkillers, also known as opioid pain relievers, include oxycodone, hydrocodone, hydromorphone, and others. Many people who abuse these painkillers become dependent. Some even move on to abusing illegal narcotics, such as heroin.
The first 92 (through uranium) occur naturally. The others are transuranics.. As of 2009, there are 118 ending with ununoctium. All together there are 117 elements on the periodic table, 94 of which occur naturally on earth. According to Wikipedia, there are 117 elements that have been isolated or synthesized, with a gap between element 116 and element 118.
Two other predicted elements were later discovered, lending further credit to Mendeleev's table. Modern day periodic tables are expanded beyond Mendeleev's initial 63 elements. Most of the current periodic tables include 108 or 109 elements. It is also important to notice how the modern periodic table is arranged. Although we have retained the format of rows and columns, which reflects a natural order, the rows of today's tables show elements in the order of Mendeleev's columns.