It is the substance that is totally consumed when the chemical reaction is complete.
A compound is a substance formed when two or more chemical elements are chemically bonded together. In mixtures, the substances present are not chemically bonded together.
Draw CO2, C in the middle and O on each side. O has 6 e- and C has 4, so 6+6+4= 14 e-.
The cell membrane performs those functions. It is the outer layer of a cell and it creates a barrier, regulates material entry and exit, uses chemical signals, and creates structure.
An Exothermic reaction releases energy into the surroundings and so the products have more potential energy then the reactants. The enthalpy change is a negative value. Whereas, an endothermic reaction involves the absorption of energy into the system and so the reactants have more potential energy than the products. The enthalpy change is a positive value. This is clearly represented in energy profile diagrams.
