An experimenter is interested in studying the relationship between hunger and aggression. She decides that she will measure aggression by counting the number of times a participant hits a punching bag. In this case, her definition of aggression is the number of times the participant hits the bag.

Explanation:

The operational definition is the description of a specific process, or set of validation tests, accessible to more persons than the definer (i.e., said to be publicly accessible), where it can be repeatedly measured or tested

Operational definitions are also used to define system states or (nonspecific) physical objects by the description of a specific process of preparation which can be repeated

For example in the given example experimenter is using the case of hitting a punching bag to measure the level of aggression in someone

enzyme speed up the reactions

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.