elements type bonds forms determined arrangement electrons orbitals particularly outermost valence electrons arrangements reflected position elements periodic table ref name mcsween based position elements fall broad groups alkali metals alkaline earth metals transition metals semi metals also known metalloids halogens noble gases lanthanides actinides ref name mcsween another useful classification scheme geochemistry goldschmidt classification places elements four main groups ''lithophiles'' combine easily oxygen elements include na k si al ti
Natural science Chemistry Geochemistry