what did the periodic table help scientists discover? A. elements not yet known to exist B. elements that are harmful C. elements that no longer exist D. elements that are radioactive

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

Which of the following statements best explains why chemistry is testable a) it can measure data by experiments b) it cannot add new evidence c) it cannot be verified d) it is biased

Silver is a white metal that is an excellent conductor. silver tarnishes when exposed to air and light. the density of silver is 10.49 g/cm3. the melting point is 962oc and the boiling point is 2000oc. a chemical property of silver is