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 is a warrior on an undercover assignment regarding matters of political import. The first episode originally aired on December 12, 2014, but a fire on December 13 destroyed the "More Than a Maid" set in Yeoncheon County and resulted in the death of one crew member, script coordinator Yeom Hye-sun. In the aftermath, the series went on hiatus for six weeks. A new set was constructed in Yeongjongdo, and filming resumed on January 12, 2015. A re-edited version of the first episode aired on January 23, 2015. In the table below, the blue numbers represent the lowest ratings and the