Radium is a chemical element in the Periodic Table marked with the atomic number of 88 and with the chemical symbol Ra. This chemical element belongs to period 7 elements and the Alkaline Earth Metals category. Similar to the rest of the Alkaline Earth Metal elements Radium possesses various metallic properties. In the Periodic Table Radium is preceded by Francium and is followed by Actinium.


Radium is a light and volatile Alkaline Earth Metal, which is the only radioactive chemical element among the Alkaline Earth Metals. It shares many group trends with the rest of the Alkaline Earth Metals, although compared to them it is highly toxic and quite inapplicable when it comes to biological uses for humans and other living organisms on Earth, or to various commercial applications due to its high chemical reactivity and its noteworthy high radioactivity. Radium can be found in small traces in Thorium and Uranium ores.


Physical Characteristics of Radium

In terms of physical properties Radium shares a variety of group trends with other Alkaline Earth Metals in the Periodic Table. It is quite lighter than most metallic elements of group 2 and is noteworthy volatile. It appears in a solid shape with a body-centered cubic crystal structure. Radium has a silvery-white metallic luster, which gets tarnished when the element is exposed to the nitrogen in the atmosphere, and the metallic luster vanishes into a thin black layer. Radium’s melting points and boiling points are relatively high. Its density is higher than the ones of other Alkaline Earth Metals and it is highly reactive.


Chemical Properties of Radium


Atomic Number – 88

Group – 2

Period – 7

Block – s

Electronic Configuration – 7s2

Relative Atomic Mass – 226 (226 g/mol)

Molecular Weight – 226

Electronegativity – 0.9

Density (G CM-3) – 5.5 g/cm3 at room temperature

Melting Point – 973 K; 700 °C; 1292 °F

Boiling Point – 2010 K; 1737 °C; 3159 °F

Atomic Radius – 200 pm

Isotopes – 1

Electronic Shell – 2, 8, 18, 32, 18, 8, 2


Discovery of Radium

The chemical element Radium was firstly discovered back in late 1898 by a French-Polish chemist and physicist, named Marie Curie, and her husband, Pierre Curie. They were studying a sample of uraninite and they discovered a new radioactive chemical element in it after they separated the Uranium from the ore. Marie and Pierre named the element after the Latin word “radius”, which means “ray”, because they acknowledged that Radium had the power to emit energy formed as rays.


The very first pure isolation of the chemical element was carried out through electrolysis in 1911 by Marie Currie and André-Louis Debierne.


Recognized by: Marie Curie and Pierre Curie (1898)

Known and discovered by: Marie Curie and Pierre Curie (1898)

Named by: Marie Curie and Pierre Curie (1898)


Uses and role of Radium

Due to the fact that this Alkaline Earth Metal is highly radioactive and toxic it does not play any known biological role to human beings and other living organisms on Earth. For the same reasons Radium does not have valuable commercial uses.


However, the element did have several applications in the past. It was used mainly in radio-luminescent devices and in radioactive quackery as a radioactive source. Nowadays the toxicity of the element has made it unusable, as other safer elements are used as substitutes for Radium. The element was once used as an ingredient for tooth paste, luminescent paint, creams, and some food items. Outdated medicine used it in some medical treatments, which were later discarded as they posed health dangers leading to cancer, genetic mutation and anemia. Nowadays Radium is only used in modern medicine as a way to cure some types of bone cancer.


Radium on Earth

As Radium is highly toxic and noteworthy radioactive it cannot exist freely in its natural state on Earth. Instead, it can be found in small traces in some Uranium and Thorium ores, like uraninite and other minerals. Radium exists on our planet in the Earth’s crust and in tiny traces in seawater.



It has been discovered that in spite of its dangerous properties Radium can still be used in various radiography devices, which are similar to X-rays, and serve to locate and discover flaws in various allows, elements and materials.