What does a negative A Hf for a molecule mean? O A. Energy was added when the molecule was formed from its
elements.
O B. Energy was released when the molecule went through a phase
change.
C. Energy was released when the molecule was formed from its
elements.
O D. Energy was added when the molecule changed phases.

Joe shines white light into a bowl half full of water at an angle of incident of 27.5°. calculate the angle of refraction in the water given the indices of refraction for air and water are 1.00 and 1.36, respectively.

How many moles are contained in 5.6 l of h2 at stp

3.09 lab: reaction of metals 1 which combinations of substances resulted in a chemical change? for each metal that participated in a chemical change, write the type of metal it is, based on your examination of the periodic table. were there any metallic compounds that did not react with either the acid or the base? write the type of metal, based on your examination of the periodic table. make a general statement about the reactivity of the metals in this experiment.