A097478 Atomic numbers of halogens in the periodic table.

9, 17, 35, 53, 85, 117

Offset: 1

Author

Parthasarathy Nambi, Sep 19 2004

Keywords

• nonn

Comments

The halogens are all on the second rightmost column of the periodic table. (The rightmost column belongs to the noble gases.) - Alonso del Arte, Apr 26 2011

Halogens: 9, fluorine (F); 17;,chlorine (Cl); 35, bromine (Br); 53, iodine (I); 85, astatine (At); and 117, tennessine (Ts). - Daniel Forgues, Jul 13 2015, Luca Khan, Sep 09 2024

References

• Monica Halka and Brian Nordstrom, Halogens and Noble Gases, Facts On File (2010), Part 1: The Halogens.

Links

• Bodner Research Web, The Chemistry of the Halogens
• Royal Society of Chemistry, Periodic Table, 2015.
• Wikipedia, Halogen

Crossrefs

Cf. A099955, alkali metals; A099956, alkaline earth metals; A101648, metalloids; A101647, nonmetals (except halogens and noble gases); A018227, noble gases; A101649, poor metals.

Formula

a(1) = 9; a(n) = a(n-1) + 2 * (ceiling(n/2) + 1)^2, 2 <= n <= 6.