Kernels of corn are heated and become popcorn. why is this a chemical change? a) the size and color of the corn have changed b) the kernels change due to their reaction of heat c) the volume of the kernels expand d) the mass of the kernels increase

b is correct. the heat is what activates the cereals to pop  

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? ?

6.4 cm (max) - 25 cm (min)