Which group in the periodic table of elements contains the most elements? Group 1The first vertical column or group, Group 1, the alkali metals, has the most elements in it (7, if hydrogen is included). 14, 15, 16. 18. Periodic table columns 13, 14, and 15. 3rd B or 3rd group. Noble Gases, Group 18. halogens & noble gases. Group III-B or 4th, it includes 4 elements of 'd' block and all the 28 elements of 'f' block.