Circle the choice that gives the best evidence that a chemical reaction occurred. A.
B.
C.
D.
The molecules were separated into individual atoms.
The mass of the magnesium changed.
Smoke that was trapped between the magnesium atoms was given off.
A new substance was formed.

materials water oxygen those are the things i can think of in this moment.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.