### action:

Chemical change
* All chemical changes are accompanied by chemical reactions.
* Every chemical change is accompanied by a change in energy, usually in the form of heat.
* Many chemical changes take place within the body as a result of glandular secretions.
* Most chemical changes are irreversible.
* Some chemical changes are extremely small and happen over a series of steps
  - permanent, while others can be reversed
  - occur naturally in the environment
* are a result of chemical reactions.
* are changes substances undergo when they become new or different substances
  - that result in the production of another substance
  - more permanent than physical changes
  - the basis for chemical reactions
  - what happens in the intestines when one eats at taco bell
* are, indeed, important.
* begin to appear in the brain.
* cause alterations in perception.
* consists of a combination, separation, or rearrangement of atoms.
* happen on a molecular level
  - much smaller scale
  - when atomic bonds are broken or created during chemical reactions
* involve alterations in a substance's chemical makeup
  - chemical reactions and the creation of new products
  - conversion of a set of materials into other materials
* is an action
  - any change that results in the formation of new chemical substances
  - when the composition of a substance changes
* occur almost all the time
  - during cooking
  - when the bonds between atoms in a molecule are created or destroyed
* releases or absorbs much energy.
* take place on the molecular level.

Chemical process
* All chemical processes have an ideal pH at which they are most efficient.
* Many chemical processes require tight temperature control.
* Most chemical processes involve liquids or gases
  - the collective behavior of many atoms
* are natural processes
  - physical events
* can occur within living organisms or from nonliving sources.
* increase by two or three times as temperature rises.
* is an action

Chewing
* Some chewing also occurs on leaf margins.
* allows enzymes and lubricants released in the mouth to further digest food
  - the mouth to further digest, or break down, food
  - fun, therapeutic, and it helps keep the teeth clean
* reduces stress and helps control barking
  - the size of food particles and the saliva moistens food
* releases mercury from fillings.

### action | chewing:

Destructive chewing
* behavioral problem and needs training to overcome.
* can be a major problem with young Airedales.
* is another behavior problem that can develop in dogs left outside
  - the most common avenue for release of trapped energy

Efficient chewing
* means faster digestion, as the material is broken into smaller pieces.
+ Ornithopod
  * Their major evolutionary advantage was the progressive development of a chewing apparatus that became the most sophisticated ever developed by a reptile. They had beaks, multiple teeth rows, cheek pouches and true chewing. Efficient chewing means faster digestion, as the material is broken into smaller pieces.

### action:

Chromatography
* allows the distribution of the size of fragments to be determined.
  - much used in biochemistry and analytical chemistry
  - unique because of three reasons
* often involves laborious separations.
  * ' way to separate single chemical compounds from mixed substances that depends on the speed at which they move through special 'media', or chemical substances. The mobile phase flows through the stationary phase. Chromatography is much used in biochemistry and analytical chemistry.
* permits scientists to separate diverse mixtures of closely related compounds.
* separates molecules by their relative migration rates
  - phases dissolved in liquid
  - things dissolved in liquid