Human activities would have the least immediate impact on the formation of fossil fuels because the fossil fuels are not affected the formation of fossil fuels. The formation of fossil fuels takes millions of years because it is a very slow process. Human activities greatly affected the coral reef bleaching, over population and Eutrophication due to the release of pollutant gases in the atmosphere that greatly impact the environment.
During Physical Change there would be a re-arrangements of atoms or molecules, changes of the arrangement may be change in the distance between atoms or molecules, change in the crystal form.
Mitosis forms two daughter cells. The daughter cells will be exactly the same as the parent cell. Skin cells, liver cells, and generally all somatic cells undergo mitosis besides sex cells.