Chemical elements and antielements
The antielements are not yet produced on Earth (except a few) and here I'll mention just the possibilities
Well, you know probably that there were produced some chemical
antielements --
antihydrogen,
antihelium. Here I want to make a list of the elements and the (real or possible) antielements (like gold - antigold. By the way there is another meaning of 'antigold' -- "(finance, historical) Opposing the use of gold as a medium of exchange."
https://en.wiktionary.org/wiki/antigold https://creativecommons.org/licenses/by-sa/3.0/):
The list
1 H Hydrogen
Antihydrogen2 He Helium
Antihelium3 Li Lithium
Antilithium4 Be Beryllium
Antiberyllium5 B Boron
Antiboron6 C Carbon
Anticarbon7 N Nitrogen
Antinitrogen8 O Oxygen
Antioxygen9 F Fluorine
Antifluorine10 Ne Neon
Antineon11 Na Sodium
Antisodium12 Mg Magnesium
Antimagnesium13 Al Aluminium
Antialuminium14 Si Silicon
Antisilicon15 P Phosphorus
Antiphosphorus16 S Sulfur
Antisulfur17 Cl Chlorine
Antichlorine18 Ar Argon
Antiargon19 K Potassium
Antipotassium20 Ca Calcium
Anticalcium21 Sc Scandium
Antiscandium22 Ti Titanium
Antititanium23 V Vanadium
Antivanadium24 Cr Chromium
Antichromium25 Mn Manganese
Antimanganese26 Fe Iron
Antiiron27 Co Cobalt
Anticobalt28 Ni Nickel
Antinickel29 Cu Copper
Anticopper30 Zn Zinc
Antizinc31 Ga Gallium
Antigallium32 Ge Germanium
Antigermanium33 As Arsenic
Antiarsenic34 Se Selenium
Antiselenium35 Br Bromine
Antibromine36 Kr Krypton
Antikrypton37 Rb Rubidium
Antirubidium38 Sr Strontium
Antistrontium39 Y Yttrium
Antiyttrium40 Zr Zirconium
Antizirconium41 Nb Niobium
Antiniobium42 Mo Molybdenum
Antimolybdenum43 Tc Technetium
Antitechnetium44 Ru Ruthenium
Antiruthenium45 Rh Rhodium
Antirhodium46 Pd Palladium
Antipalladium47 Ag Silver
Antisilver48 Cd Cadmium
Anticadmium49 In Indium
Antiindium50 Sn Tin
Antitin51 Sb Antimony
Antiantimony52 Te Tellurium
Antitellurium53 I Iodine
Antiiodine54 Xe Xenon
Antixenon55 Cs Caesium
Anticaesium56 Ba Barium
Antibarium57 La Lanthanum
Antilanthanum58 Ce Cerium
Anticerium59 Pr Praseodymium
Antipraseodymium60 Nd Neodymium
Antineodymium61 Pm Promethium
Antipromethium62 Sm Samarium
Antisamarium63 Eu Europium
Antieuropium64 Gd Gadolinium
Antigadolinium65 Tb Terbium
Antiterbium66 Dy Dysprosium
Antidysprosium67 Ho Holmium
Antiholmium68 Er Erbium
Antierbium69 Tm Thulium
Antithulium70 Yb Ytterbium
Antiytterbium71 Lu Lutetium
Antilutetium72 Hf Hafnium
Antihafnium73 Ta Tantalum
Antitantalum74 W Tungsten
Antitungsten75 Re Rhenium
Antirhenium76 Os Osmium
Antiosmium77 Ir Iridium
Antiiridium78 Pt Platinum
Antiplatinum79 Au Gold
Antigold80 Hg Mercury
Antimercury81 Tl Thallium
Antithallium82 Pb Lead
Antilead83 Bi Bismuth
Antibismuth84 Po Polonium
Antipolonium85 At Astatine
Antiastatine86 Rn Radon
Antiradon87 Fr Francium
Antifrancium88 Ra Radium
Antiradium89 Ac Actinium
Antiactinium90 Th Thorium
Antithorium91 Pa Protactinium
Antiprotactinium92 U Uranium
Antiuranium93 Np Neptunium
Antineptunium94 Pu Plutonium
Antiplutonium95 Am Americium
Antiamericium96 Cm Curium
Anticurium97 Bk Berkelium
Antiberkelium98 Cf Californium
Anticalifornium99 Es Einsteinium
Antieinsteinium100 Fm Fermium
Antifermium101 Md Mendelevium
Antimendelevium102 No Nobelium
Antinobelium103 Lr Lawrencium
Antilawrencium104 Rf Rutherfordium
Antirutherfordium105 Db Dubnium
Antidubnium106 Sg Seaborgium
Antiseaborgium107 Bh Bohrium
Antibohrium108 Hs Hassium
Antihassium109 Mt Meitnerium
Antimeitnerium110 Ds Darmstadtium
Antidarmstadtium111 Rg Roentgenium
Antiroentgenium112 Cn Copernicium
Anticopernicum113 Uut Ununtrium
Antiununtrium114 Fl Flerovium
Antiflerovium115 Uup Ununpentium
Antiununpentium116 Lv Livermorium
Antilivermorium 117 Uus Ununseptium
Antiununseptium118 Uuo Ununoctium
Antiununoctium (The unnamed elements 113, 115, 117, and 118 have recently been confirmed, and the following names have been proposed by their discoverers. We show them here with their 'anti-' names):
113 Nh Nihonium
Antinihonium115 Mc Moscovium
Antimoscovium117 Ts Tennessine
Antitennessine118 Og Oganesson
Antioganesson- - -
Source of the list of chemical elements:
https://en.wikipedia.org/wiki/List_of_chemical_elements.