Asolution is a
a. combination of isotopes.
b. chemical reaction.
c. mixture in which the substances are evenly spread out.
d. mixture in which undissolved substances do not settle out.

Why was the sample heated in step 5? describe the chemical principles involved in the reasoning behind this step?

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h,o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

Explain how the parts of the peripheral nervous system work with the central nervous system to produce a response to the stimulus