What is the density of an object that has a mass of 500g and a volume of
10mL?

What element breaks down into yttrium-90?

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility

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.