is aluminum foil a compound element or mixture?

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?