In an experiment, a rat can choose between hitting a blue button (which provides a snack) or a yellow button (which provides a shock). in each round of the experiment, the buttons may or may not switch colors. this experiment combines elements of which two researchers?

Donder and Skinners

Explanation:

Donder and Skinner both were behavioral psychologists. They both work on the experiment related to rat learning of behavior. This experiment deals with the response and positive reinforcement. Skinner theory was on ope-rant conditioning and conduct many experiments on animals like a rat. He used a box in his experiment that is called the Skinner bore experiment. The experiment deals with and even show the positive reinforcement. Francis Donder was an ophthalmologist. He worked on subtraction and reaction time measurements in his experiment. He also wants to study the reaction time of subtraction in the rat and functioning of the frontal lobe so he contributes with Skinner in his experiment. They work together in that experiment.

forty niners migrated west due to gold discovery in california and it the west was a new place for hope this : )

explanation:

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.