Astatine (At)
Astatine (At, element 85) is a halogen in group 17, period 6. Atomic mass 210, electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵, uses and facts.
About Astatine
Astatine is a halogen with the symbol At and atomic number 85. It is a solid at room temperature, and it sits in group 17, period 6 of the periodic table. Astatine was discovered in 1940 by Dale R. Corson.
Astatine key facts
- Atomic number: 85
- Symbol: At
- Atomic mass: 210 u
- Category: halogen
- Group: 17
- Period: 6
- State at room temperature: solid
- Electron configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Electronegativity (Pauling): 2.2
- Melting point: 575 K (301.85 °C)
- Boiling point: 610 K (336.85 °C)
- Density: not known
- Common oxidation states: −1, +1, +3, +5, +7
Electron configuration
The electron configuration of astatine is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵. The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells. Astatine has 7 valence electrons.
Uses of astatine
- Cancer treatment (research)
- Radioactive tracers
Did you know?
Astatine is the rarest naturally occurring element, less than 25 grams exist in Earth's crust at any time.
Other elements in group 17 and neighbours
Frequently asked questions
What is the atomic number of astatine?
The atomic number of astatine is 85, which means every astatine atom has 85 protons.
What is the electron configuration of astatine?
The electron configuration of astatine is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵.
What group and period is astatine in?
Astatine is a halogen in group 17, period 6.
What state is astatine at room temperature?
Astatine is a solid at room temperature.
What is astatine used for?
Astatine is used for cancer treatment (research), radioactive tracers.