The rate constant, k, for a first-order reaction is equal to 4.2 × 10-4 s-1. What is the half-life for the reaction?

Approximately .

Explanation:

In a first-order reaction, the reaction rate is proportional to the concentration of a single reactant (call it .) The half-life of that first-order reaction would be the time it takes for (concentration of ) to drop to its initial value.

The equation for the half-life of a first-order reaction is

,

where is the rate constant of this reaction.

In this case,

.

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