88
Ra
226
Radium (Ra)
Element 88 · Period 7 · Group 2
alkaline-earth
solid at room temp
s-block
radioactive
About Radium
Highly radioactive. Discovered by Marie and Pierre Curie. Once used in luminous paint (now banned).
Physical Properties
Atomic Mass
226 u
State at 25°C
Solid
Melting Point
700 °C
Boiling Point
1413 °C
Density
5.5 g/cm³
Magnetism
Paramagnetic
Atomic Properties
Electron Configuration
[Rn] 7s²
Electron Shells
2, 8, 18, 32, 18, 8, 2
Electronegativity
0.9
Atomic Radius
283 pm
Ionization Energy
509 kJ/mol
Oxidation States
+2
Discovery & History
Discovered By
Marie Curie
Discovery Year
1898
Named By
Marie Curie
Name origin: Latin: radius (ray)
Frequently Asked Questions
- Is Radium a metal, nonmetal, or metalloid?
- Radium is classified as a alkaline-earth.
- What state is Radium in at room temperature?
- Radium is a solid at standard room temperature (25°C).
- What is the atomic mass of Radium?
- Radium has an atomic mass of 226 atomic mass units (u).
- Who discovered Radium?
- Radium was discovered by Marie Curie in 1898.
- Where is Radium on the periodic table?
- Radium is element number 88, located in period 7 and group 2.