Answer:
Cd, Cr, Cu, Hg, Pb, and Zn
Gametes or sex cells (sperm and eggs) contain half the number of chromosomes that exist in autosomal cells; they are haploid. Therefore in the case where the diploid number of chromosomes is 52, the haploid number would be half of that, meaning 52/2 = 26.
Carbon dioxide is the compound in photosynthesis, I'm pretty sure