Question

Trace levels of this element are detected using particle-induced gamma ray emission or an electrode that uses a “total ionic strength adjustment buffer.” Telomer (“TEE-loh-mer”) alcohols containing this element oligo·merize to form a short-chain propylene oxide dimer acid called GenX. The last digit of a molecule’s R-number indicates its number of atoms of this element, in line with empirical nomenclature. In March 2023, the EPA set a four-parts-per-trillion (10[1])concentration (-5[1])limit on a carcinogenic octane·sulfonic acid substituted (10[1])with (10[1])this (10[1])element (10[1])that is still used in firefighting foam. Aluminum (10[1])smelting is the main source of water pollution by this nonmetal found in cryolite. (10[1]-5[1])Because (10[1])this element (10[1])forms the strongest single bond with carbon, inert alkyl (10[1]-5[1])surfactants (10[1]-5[1])containing (10[1])it are colloquially (10[1])called “forever (10[1])chemicals.” For 10 points, (10[1])name this element (10[1])found with carbon and chlorine (10[3]-5[1])in freons and other ozone-destroying molecules. ■END■ (10[5])

ANSWER: fluorine [or F; reject “fluoride”] (“Forever chemicals” include PFAS, or perflouroalkyl and polyfluoroalkyl substances. The ozone-destroying molecules are CFCs, or chlorofluorocarbons.)
<Chemistry>
= Average correct buzz position

Summary

2023 ACF Nationals04/22/2023Y24100%0%21%110.25

Buzzes

PlayerTeamOpponentBuzz PositionValue
Vittal BhatNorth Carolina AHarvard A6610
Natan HoltzmanStanford AGeorgia Tech A67-5
Nikhil ChellamNorthwestern AMIT A7410
Geoffrey ChenCornell AOhio State A7510
Aidan FeinVanderbilt AJohns Hopkins A7610
Richard NiuCornell BIndiana A7710
Isak JatoiSouth Carolina AGeorgia Tech B8510
Frederick Rivas-GiorgiYale BPenn A99-5
Shahar SchwartzUC Berkeley AColumbia A9910
Jason HongBrown AFlorida A10010
Rohan ShelkeUC Berkeley BImperial A10210
Matt SchiavonePurdue AHouston A11110
Daniel MaYale ADuke A111-5
John MarvinChicago BChicago A11210
Ethan AshbrookMinnesota AToronto A112-5
Jacob Van OorschotMcGill APenn State A11310
Todd MaslykMichigan ANYU A11610
Robert CondronChicago CTexas A11810
Jeya IyaduraiFlorida BRutgers B12210
Kevin ParkClaremont AIllinois A12510
Benjamin WeinerMinnesota BColumbia B13010
Matthew LehmannWUSTL AMaryland A13010
Vedul PalavajjhalaWUSTL BIowa State A130-5
Joseph ChambersVirginia ARutgers A13010
Arya KarthikGeorgia Tech AStanford A13710
Ashish SubramanianDuke AYale A13710
Sky LiToronto AMinnesota A13710
JD KrothIowa State AWUSTL B13710
Vishal KanigicherlaPenn AYale B13710