When students enter a class, they tend to spread themselves out (provided there are enough desks to do so). in biological terms, this effect would be: ?

In biological terms, this effect would be "diffusion".

Diffusion is a spontaneous movement of particles from a territory of high focus to a zone of low fixation. (ex. tea seasoning moving from a zone of high to low fixation in heated water.)  

Diffusion predominantly happens in gaseous state or inside gas atoms and fluid molecules.(e.g. The particles of 2 gases are in steady movement and if the layer isolating them is evacuated the gases will blend due to arbitrary speeds.)

d

explanation:

it establishes america’s basic laws and fundamentals to its citizens.

not  

cuba  

russia  

iraq  

el salvador  

explanation:

known as the land of volcanoes, el salvador has visit seismic tremors and volcanic movement. it is the main nation in central america that does not have a coastline on the caribbean sea. about portion of all salvadorans live in the wide open. they are poor and don't have power or running water in their homes. in 1525, pedro de alvarado, a lieutenant of cortés's, vanquished el salvador. el salvador, with alternate nations of central america, pronounced its freedom from spain on sept. 15, 1821, and was a piece of a league of central american states until the point when that association broke up in 1838.