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A097478 Atomic numbers of halogens in the periodic table. 5
9, 17, 35, 53, 85, 117 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

From Daniel Forgues, Jul 12-13 2015: (Start)

Hydrogen is not a halogen: although its valence shell is one electron short of being full (like the halogens), it has only one valence electron (like the alkali metals).

Halogens: 9: fluorine (F), 17: chlorine (Cl), 35: bromine (Br), 53: iodine (I), 85: astatine (At) and 117: Ununseptium (Uus).

Astatine: behaves chemically like iodine, highly radioactive.

Ununseptium: metal (...then not halogen?), highly radioactive. (End)

REFERENCES

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

LINKS

Table of n, a(n) for n=1..6.

Bodner Research Web, The Chemistry of the Halogens

Bodner Research Web, The Chemistry of Hydrogen

Royal Society of Chemistry, Periodic Table, 2015.

FORMULA

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

CROSSREFS

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

Sequence in context: A146236 A147279 A173788 * A147026 A055393 A147082

Adjacent sequences:  A097475 A097476 A097477 * A097479 A097480 A097481

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Sep 19 2004

STATUS

approved

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Last modified November 20 05:07 EST 2019. Contains 329323 sequences. (Running on oeis4.)