Oxygen

tin

Hydrogen (H) - 1 Helium (He) - 2 Lithium (Li) - 3 Beryllium (Be) - 4 Boron (B) - 5 Carbon (C) - 6 Nitrogen (N) - 7 Oxygen (O) - 8 Fluorine (F) - 9 Neon (Ne) - 10 Sodium (Na) - 11 Magnesium (Mg) - 12 Aluminium (Al) - 13 Silicon (Si) - 14 Phosphorus (P) - 15 Sulfur (S) - 16 Chlorine (Cl) - 17 Argon (Ar) - 18 Potassium (K) - 19 Calcium (Ca) - 20 Scandium (Sc) - 21 Titanium (Ti) - 22 Vanadium (V) - 23 Chromium (Cr) - 24 Manganese (Mn) - 25 Iron (Fe) - 26 Cobalt (Co) - 27 Nickel (Ni) - 28 Copper (Cu) - 29 Zinc (Zn) - 30 Gallium (Ga) - 31 Germanium (Ge) - 32 Arsenic (As) - 33 Selenium (Se) - 34 Bromine (Br) - 35 Krypton (Kr) - 36 Rubidium (Rb) - 37 Strontium (Sr) - 38 Yttrium (Y) - 39 Zirconium (Zr) - 40

U

Oganesson!

Iron