Achocolate chip cookie is an example of what? element compound heterogeneous mixture homogeneous mixture

What overall charge must all compounds have

What properties would have caused early researchers to name hydrogen "inflammable air”

How can a scientist assess whether a pure niobium (nb) sample is responsible for contaminating the lab with radioactivity? test the niobium sample to see whether it now contains other elements. test the niobium sample for the presence of niobium oxide compounds. heat the niobium, and see if the level of radioactivity in the lab increases. place the niobium under pressure, and see if the level of radioactivity in the lab increases.