What is Radium?
[[File:Radium226.jpg|thumb|Piece of radium metal (Radium-226)]] {{wiktionary}} '''Radium''' is a [[chemical element]]. The [[Chemical symbol|symbol]] for radium is '''Ra''', and its [[atomic number]] is 88. It was discovered by [[Marie Curie]] and [[Pierre Curie]] in the form of radium chloride in 1898. It is a slivery-white [[alkaline earth metal]], but it turns black quickly when it is exposed to [[nitrogen]] in the [[air]]. All [[isotope]]s of radium are [[Ionizing radiation|radioactive]]. The radioactivity of radium causes it to [[Radioluminescence|glow in the dark]]. Radium is used in many things, such as glowing watches, which are now banned because they can cause [[radiation poisoning]]. Some of the things radium was used for are now made using less dangerous radioactive elements, such as [[promethium]]. It can be used in treating cancer.<ref>{{Cite web|title=Radium 223 (Xofigo) {{!}} Cancer treatment {{!}} Cancer Research UK|url=https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/radiotherapy/internal/radioactive-liquid-treatment/radium-223|access-date=2021-06-08|website=www.cancerresearchuk.org}}</ref> In nature, radium is found in tiny amounts in [[uranium]] and [[thorium]] [[Ore|ores]]. It does not exist naturally inside of people or other living things; it is dangerous when [[Exposure (toxicology)|taken in]] because it takes the same place as [[calcium]]. == History == Radium was discovered by [[Marie Curie]] and her husband [[Pierre Curie]] on 21 December 1898.<ref>{{Cite book|title=CRC handbook of chemistry and physics: a ready-reference book of chemical and physical data|url=https://archive.org/details/crchandbookofche0000unse_e9l0|date=2011|publisher=CRC Press|isbn=978-1-4398-5511-9|editor-last=Haynes|editor-first=William M.|edition=92nd ed., 2011 - 2012|location=Boca Raton, Fla.|editor-last2=Lide|editor-first2=David R.}}</ref> They found that some radioactive [[Mineral|minerals]] had unknown compounds left over after removing uranium and [[barium]]. The unknown compounds