Consider the following intermediate chemical equations. What is the enthalpy of the overall chemical reaction Upper P upper C l subscript 5 (g) right arrow upper P upper C l subscript 3 (g) plus Uper C l subscript 2 (g).?

-999 kJ
-250. kJ
250. kJ
999 kJ

Is this a single replacement reaction or there is no

Which statement is true about this reaction? 14n+1h 15o it is a practical source of energy on earth. it occurs only outside the solar system. its product is heavier than each of its reactants. it shows the critical mass of an element.

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.