What is Conservation of mass?
The '''law of conservation of mass''' states that [[mass]] can neither be created nor [[wikt:destroy|destroyed]] in a chemical reaction. Thus, the amount of [[matter]] cannot change. [[Antoine Lavoisier|Sir Antoine Lavoisier]] promoted this idea. This law says that when a [[chemical reaction]] rearranges atoms into a new product, the [[mass]] of the reactants ([[chemical]]s before the chemical reaction) is the same as the mass of the [[Product (chemistry)|product]]s (the new [[chemical]]s made). More simply, whatever you do, you will still have the same amount of stuff. The law is accurate for all chemical reactions. However, certain [[nuclear reaction]]s (fusion and fission) can convert a small part of the [[Mass-energy equivalence|mass into energy]]. But if this energy is turned back into mass, you will have the same amount of mass. == History == The principle of conservation of mass was first outlined by [[Mikhail Lomonosov]] (1711&ndash;1765) in 1748. He proved it by experiments—though this is sometimes challenged.<ref>*{{Cite journal | volume = 10 | issue = 3 | pages = 119–127 | last = Pomper | first = Philip | title = Lomonosov and the discovery of the law of the conservation of matter in chemical transformations | journal = Ambix | date = 1962| doi = 10.1179/amb.1962.10.3.119 }}<br>{{Cite book | publisher = Harvard University Press | last = Lomonosov | first = Mikhail Vasil’evich | others = Henry M. Leicester (transl.) | title = Mikhail Vasil'evich Lomonosov on the corpuscular theory | location = Cambridge, Mass. | year = 1970 | at = Introduction, p.&nbsp;25}}</ref> [[Antoine Lavoisier]] (1743&ndash;1794) had expressed these ideas in 1774. Others whose ideas pre-dated the work of Lavoisier include [[Joseph Black]] (1728&ndash;1799), [[Henry Cavendish]] (1731&ndash;1810), and [[Jean Rey (physician)|Jean Rey]] (1583&ndash;1645).<ref>[http://www.eric.ed.gov/ERICWebPortal/search/recordDetails.jsp?searchtype=keyword&ERICExtSearch_SearchValue_0=EJ128341&ERICExtSearch_SearchType_0=kw&_pageLabel=RecordDeta