When a 14.2-g sample of mercury (ii) oxide is decomposed into its elements by heating, 13.2 g hg is obtained. what is the percent composition of the compound?

18. use the activity series to predict whether the following synthesis reaction will occur. write the chemical equations for the reaction if it's predicted to occur. (s) + o2(g) -> *note: it is possible.*

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.