Hydrogen is the chemical element with the symbol H and atomic number 1.
Lithium is a chemical element with the symbol Li and atomic number 3.
Sodium is a chemical element with the symbol Na and atomic number 11.
Potassium is a chemical element with the symbol K and atomic number 19.
Caesium is a chemical element with the symbol Cs and atomic number 55.
Mercury is a chemical element with the symbol Hg and atomic number 80.
Thallium is a chemical element with the symbol Tl and atomic number 81.
Lead is a chemical element with the symbol Pb (from the Latin plumbum) and atomic number 82.
Bismuth is a chemical element with the symbol Bi and atomic number 83.
Polonium is a chemical element with the symbol Po and atomic number 84.
Astatine is a radioactive chemical element with the symbol At and atomic number 85.