What does a scientist observe in a chemical's reaction rate? the speed at which the reactants change to products over a given time. the speed at which the reactants are formed over a given time the speed at which the reactants reach chemical equilibrium over a given time , , the speed at which the reactants reach chemical equilibrium over a given time

The speed at which the reactants change to products over a given time.

Explanation:

A chemical's reaction rate is the change in the concentration of a reactant or a product with time (in moles per second).

Remember that during a chemical reaction, reactants are converted to products. Or what is the same, products are formed at the expense of reactants. This can be represented:

reactants → products

Therefore, the progress of a reaction can be followed measuring the decrease in concentration of the reactants or the increase in concentration of the products.

According to the temperature and other parameters, the reaction rate can increase or decrease.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).