Why are some metal elements easier to extract from metal ores than others?
. .- - - - - t " " " " - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . W-cc Y"7 • , { q.""\'A.JlAA ,,,- ~_ b V ,~ lA~"",,--, '" .L.r s]. •.~_. 1 - - - - - - 1 1.- -kY".v~'-! -")h cS ~ j., ., ,(J'r-::'--,=..::':...:U p'""V\ yLT JO m - " VIt.\' _ 5 E "JC ~ -!'1'..!it.~T 1_______ v _ V __ :rr..::..,....!.I'.:::""'~j(_ l.....'T ~+- v-e.P.k< ..D,:;t.V'o'( Pl"ess~",