fourth period
The third period is similar to the second, except the 3s and 3p sublevels are being filled. Because the 3d sublevel does not fill until after the 4s sublevel, the fourth period contains 18 elements, due to the 10 additional electrons that can be accommodated by the 3d orbitals.
Many angiosperm species rely on the interaction between animals and their flowers for reproduction. As insects, birds or other animals move from one flower to another feeding on nectar, they commonly distribute pollen from flower to flower as they go which leads to plants being pollinated and seeds to be produced.
Wish I can help, but I don't take chemistry. :(
fly sry
Decomposer, decomposers include fungous, bacteria, worms. They break down trash and bad things and concert it to soil.