To test the quality of water sources in her area, shameka collects five samples from each water source and tests the quality of each sample.

which important step of scientific design is shameka conducting?

repetition
replication
verification of results
using controlled variables

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation: