--element format = {"El",<group>,<period>}

local groups = {
  {"alkali metals",{
  
    {"Li",1,2,3},
    {"Na",1,3,11},
    {"K" ,1,4,19},
    {"Rb",1,5,37},
    {"Cs",1,6,55},
    {"Fr",1,7,87},
    
  }},
  {"alkaline earth metals",{
  
    {"Be",2,2,4},
    {"Mg",2,3,12},
    {"Ca",2,4,20},
    {"Sr",2,5,38},
    {"Ba",2,6,56},
    {"Ra",2,7,88},
    
  }},
  {"coinage metals",{
  
    {"Sc",3,4,21},
    {"Y" ,3,5,39},
    
    {"Ti",4,4,22},
    {"Zr",4,5,40},
    {"Hf",4,6,72},
    {"Rf",4,7,104},
    
    {"V" ,5,4,23},
    {"Nb",5,5,41},
    {"Ta",5,6,73},
    {"Db",5,7,105},
    
    {"Cr",6,4,24},
    {"Mo",6,5,42},
    {"W" ,6,6,74},
    {"Sg",6,7,106},
    
    {"Mn",7,4,25},
    {"Tc",7,5,43},
    {"Re",7,6,75},
    {"Bh",7,7,106},
    
    {"Fe",8,4,26},
    {"Ru",8,5,44},
    {"Os",8,6,76},
    {"Hs",8,7,107},
    
    {"Co",9,4,27},
    {"Rh",9,5,45},
    {"Ir",9,6,77},
    
    {"Ni",10,4,28},
    {"Pd",10,5,46},
    {"Pt",10,6,78},
    
    {"Cu",11,4,29},
    {"Ag",11,5,47},
    {"Au",11,6,79},
    
  }},
  {"volatile metals",{
  
    {"Zn",12,4,30},
    {"Cd",12,5,48},
    {"Hg",12,6,80},
    {"Cn",12,7,112},
    
  }},
  {"icosagens",{
  
    {"B"  ,13,2,5},
    {"Al" ,13,3,13},
    {"Ga" ,13,4,31},
    {"In" ,13,5,49},
    {"Tl" ,13,6,81},
    {"Uut",13,7,113},
    
  }},
  {"crystallogens",{
  
    {"C" ,14,2,6},
    {"Si",14,3,14},
    {"Ge",14,4,32},
    {"Sn",14,5,50},
    {"Pb",14,6,82},
    {"Fl",14,7,114},
    
  }},
  {"pnictogens",{
  
    {"N"  ,15,2,7},
    {"P"  ,15,3,15},
    {"As" ,15,4,33},
    {"Sb" ,15,5,51},
    {"Bi" ,15,6,83},
    {"Uup",15,7,115},
    
  }},
  {"chalcogens",{
  
    {"O" ,16,2,8},
    {"S" ,16,3,16},
    {"Se",16,4,34},
    {"Te",16,5,52},
    {"Po",16,6,84},
    {"Lv",16,7,116},
  
  }},
  {"halogens", {
    
    {"F"  ,17,2,9},
    {"CL" ,17,3,17},
    {"Br" ,17,4,35},
    {"I"  ,17,5,53},
    {"At" ,17,6,85},
    {"Uus",17,7,117},
  
  }},
  {"noble gases",{
  
    {"He" ,18,1,2},
    {"Ne" ,18,2,10},
    {"Ar" ,18,3,18},
    {"Kr" ,18,4,36},
    {"Xe" ,18,5,54},
    {"Rn" ,18,6,86},
    {"Uuo",18,7,118},
  
  }}
  
}

 
for i, group in ipairs(groups) do
  --print(i.." "..group[1])
  for ii, element in ipairs(group[2]) do
    print(element[1].." "..element[4])
    minetest.register_node("chemistry:"..element[1], {
      description = element[1],
      tiles = {element[1]..".png"},
      groups = {snappy=2,choppy=2,oddly_breakable_by_hand=3,flammable=3,wool=1},
    })
  end
end