Chemical substance can be transmuted into another element through a nuclear reaction. This is so, because all of the atoms in a sample of an element have the same number of protons, though they may be different isotopes, with differing numbers of neutrons. As of 2012, there are 118 known elements, about 80 of which are stable – that is, they do not change by radioactive decay into other elements. Some elements can occur as more than a single chemical substance (allotropes). For instance, oxygen exists as both diatomic oxygen (O) and ozone (O). The majority of elements are classified as metals.
More Than a Maid More Than a Maid More Than a Maid () is a 2015 South Korean television series starring Jeong Yu-mi, Oh Ji-ho, Kim Dong-wook, Lee Si-a, Jeon So-min and Lee Yi-kyung. It aired on jTBC from January 23 to March 28, 2015 on Fridays and Saturdays at 21:45 for 20 episodes. Guk In-yeob is the only daughter of a Joseon nobleman, and her beauty and style has her surrounded by plentiful admirers, among them Kim Eun-gi, a young scholar from an important family who's loved In-yeob since they were young. But one day In-yeob's father is branded a traitor, causing her