Carbon: atomic number 6, non-metal, solid, period 2.
Platinum: atomic number 78, metal, solid, group 10, period 6.
Iron: atomic number 26, metal, solid, group 8, period 4.
Hydrogen: atomic number 1, nonmetal, gas, group 1, period 1.
Cobalt: atomic number 27, metal, solid, group 9, period 4.
Arsenic: atomic number 33, metalloid, solid, group 15, period 4.
Hope this helps!! (:
