Determine the density of three pure solids on g/cm3. Choose objects of which you are sure of their identity, such as aluminum foil (crumpled or in a ball), copper wire or iron nails. Then, test an object that you think might contain one of the materials you tested. Report as to whether your data supports your hypothesis. Write a 200 word report including hypothesis, procedure, results, and conclusions. Discuss the question, "What factors cause differences in density?" Be specific.

Example: If you choose aluminum foil and test its density by doing a water displacement test. You could then choose a soda can or a can that contained some fruit, vegetable, or soup and test the can.

Example: If you choose to test copper wire, you could use a penny for your second test to see if the penny is pure copper.

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cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!