Which skeleton equation is correct for this question below: ?
calcium carbonate reacts with sulfur dioxide gas and oxygen gas to produce solid calcium sulfate and carbon dioxide gas. the correct skeleton equation for this reaction is:

a. caco(s)+so(g)+o(g) --> caso(s)+co(g)
b. caco2(s)+so2(g)+o3(> caso2(s)+co2(g)
c. caco3(s)+so2(g)+o2(g) --> caso4(s)+ co2(g)
d. ca(co3)2(s)+so2(g)+o2(> ca2so4(s)+co2(g)

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

The reactions of photosynthesis occur in the of plant cell? a.mitochondria. b. lysosomes. c. chloroplasts. d. chlorophyll