What ir absorption is characteristic of the c-h stretch in alkanes?

i thinking chemical change

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.

c. heat from the poles back down towards the equator.

the answer is d p: cell, q: organ, r: organ system, s: tissue