Why are group VIA elements called halogens??

Be sure to answer all parts. the following equilibrium constants were determined at 1123 k: c(s) + co2(g) ⇌ 2co(g) k'p = 1.30 × 1014 co(g) + cl2(g) ⇌ cocl2(g) k''p = 6.00 × 10−3 calculate the equilibrium constant at 1123 k for the reaction: c(s) + co2(g) + 2cl2(g) ⇌ 2cocl2(g) 4.68 × 10 9 (enter your answer in scientific notation.) write the equilibrium constant expression, kp: