Suppose a chemist discovers a new metallic element and names it "Xiguum" (Xi).
Xi exhibits chemical behaviour similar to an alkaline earth.
Xi(s) + Cl2(g) --> XiCl2(s)
Lattice energy for XiCl2 -2300 kJ/mol
First Ionization energy of Xi 420 kJ/mol
Second Ionization energy of Xi...