A_ is a homogeneous mixture of two or more substances. amalgamythm
compound
solute
solution
The answer is D. Solution

Covalent compounds: mastery test select the correct answer what is formed when atoms join together with a covalent bond? a. an ion b. a molecule c. a neutral atom d. a noble gas

Ahas distinct properties and composition that never vary.

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.