Concentration Definition. In chemistry, concentration refers to the amount of a substance per defined space. Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration usually is expressed in terms of mass per unit volume.
The melting of the ice cube indicates physical change has taken place
Hard question !! Is this math .. if not then oh okay cause I’m bad at math but good at everything else so let me think about it !
A: mouth. Chemical digestion begins in the mouth when enzymes in saliva begin to break down carbohydrates. Most chemical changes in digestion occur in the small intestine. Large molecules of food are broken down into smaller molecules that can be absorbed by our cells.
C, <span>Fuel cell cars do not release greenhouse gases, is the best choice. Hydrogen fuel cells do not release carbon dioxide.</span>