Eric Walker added Silica to Silicon dioxide, and added Silicon dioxide to Oxidation and oxides and Silicon

Eric Walker added Antimony and Silicon to Metalloids, and added Metalloids to Atoms, molecules, chemicals, minerals, materials and compounds

Eric Walker added a number of topics and We found a new type of stellar explosion that could explain a 13-billion-year-old mystery of the Milky Way's elements and Is It Time to Upend the Periodic Table? - The New York Times to Chemical elements, and added Chemical elements to Chemistry and Atoms, molecules, chemicals, minerals, materials and compounds

Eric Walker added Silicon dioxide and Silicates to Silicon, and added Silicon to Metalloids and Chemical elements

Eric Walker added a number of topics to Silicates, and added Silicates to Silicon and Minerals and gems