use the bond energies provided to estimate δh°rxn for the reaction below. ch2 =ch2 (g) h2(g) → ch3-ch3(g) δh°rxn = ?

Determine the empirical formula for succinic acid that is composed of 40.60% carbon, 5.18% hydrogen, and 54.22% oxygen.

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world