Understanding the scientific rationale behind Radium's position in the periodic table:
Belongs to Group 2 because it has 2 valence electrons in its outer 7s orbital (7s²).
Belongs to Period 7 because its outermost occupied shell is n=7.
Belongs to the s-block because the differentiating electrons enter the 7s subshell.
Classified as an alkaline earth metal with typical +2 oxidation chemistry.
Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.
Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.
Neutral ground state configuration. Valence electrons: 2.
Found in uranium pitchblende (uraninite) ore at an average concentration of about one gram of radium per three tonnes of uranium.
From Latin 'radius' meaning ray, reflecting its intense radioactive rays
Extremely hazardous radioisotope; behaves as a 'bone seeker' like calcium, causing severe bone cancer and marrow damage.