In which orbital would the valence electrons for carbon be placed

Carbon have 4 valence electron

The electron configuration of C is : 1s2 2s2 2ps

the outer most s and p orbital contains 4 electrons and these are the valence electron of C atom

Key: to determine the valence electron of an element, you have to refer to the group it is located in, in the periodic table. (C is in group 4 (or 14) so VE = 4)

hope its clear enough