How is density calculated?

2h2s + 3o2 2so2 + 2h2o which option gives the correct mole ratios? h2s: so2 = 2: 2 and o2: h2o = 3: 2 h2s: so2 = 2: 3 and o2: h2o = 3: 2 h2s: so2 = 4: 4 and o2: h2o = 5: 4 h2s: so2 = 4: 6 and o2: h2o = 4: 4

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

An unsaturated hydrocarbon is a hydrogen-carbon compound with a. a network solid structure b. single bonds c. single bonds in a branched-chain structure d. double or triple bonds