A concentration gradient happens when there is a change of the concentration in solution for period of time. Diffusion is the movement of molecules or ions. The relationship between the two of them is molecules diffuse down from an area with a higher concentration to a lower one. An example of this is putting dye in water.
Mass is the physical property of matter can be expressed numerically in SI units.
20 calories equals to 8.368 joules.
4.184 J is needed to raise 1 gram of water.(Heat capacity of water)
for 2 grams of water 8.368 joules.
So the answer is 16 c.
b is fastest, having the lowest activation energy (35 kJ) and is an exothermic reaction, releasing energy in the form of heat
c is slowest, having the highest activation energy (55 kJ) and is an endothermic reaction, taking in energy from its surroundings
