Why are chemical equilibria called dynamic equilibria?

Because molecules are moving so they change from reactants to products and vice versa.

Explanation:

Hello,

In this case, it is widely known that chemical equilibrium is related with such condition at which the rate of consumption of reactants and formation of products tends to zero so their concentrations remain the same over the time. For instance, if we consider the formation of hydrogen chloride at equilibrium:

We can also see that the reactants, hydrogen and chlorine are consumed to form hydrogen chloride and it also goes back to its reactants in a dynamic equilibrium (because they are constantly changing).

Best regards.

d.) the average kinetic energy of the gas particles is greater in container b because its particles move faster.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them