3 Ajustar (balancear) las ecuaciones químicas siguientes: a) \( \mathrm{Cr}+\mathrm{H}_{2} \mathrm{~S} \rightarrow \mathrm{Cr}_{2} \mathrm{~S}_{3}+\mathrm{H}_{2} \) b) \( \mathrm{CH}_{4}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \) c) \( \mathrm{Ni}(\mathrm{OH})_{3}+\mathrm{H}_{2} \mathrm{MnO}_{4} \rightarrow \mathrm{Ni}_{2}\left(\mathrm{MnO}_{4}\right)_{3}+\mathrm{H}_{2} \mathrm{O} \) d) \( \mathrm{C}_{3} \mathrm{H}_{8}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \) e) \( \mathrm{Pb}(\mathrm{OH})_{4}+\mathrm{HCl} \rightarrow \mathrm{PbCl}_{4}+\mathrm{H}_{2} \mathrm{O} \) f) \( \mathrm{CsOH}+\mathrm{H}_{2} \mathrm{Se} \rightarrow \mathrm{Cs}_{2} \mathrm{Se}+\mathrm{H}_{2} \mathrm{O} \)

L'uraninite, ou pechblende, est un minéral de formule chimique \( \mathrm{UO}_{2} \). Les gisements d'uraninite sont datés uniquement entre 3,5 et 2,2 milliards d'années. Its sont utilisés notamment pour extraire l'uranium uti- lisé dans l'industrie nucléaire civile et militaire. Ces gisements se forment dans des milieux réducteurs, c'est-à-dire en absence de dioxygène. Question Expliquer en quoi l'uraninite est un indice de l'évolution de la teneur en dioxygène terrestre.

There are different types of food coloring available in most grocery stores- one that is water-based, and one that is oil-based. The oil-based food coloring works best in chocolates, in fry-oil to color fried foods, and in food with high butter contents. Based off of this information and knowing that substances of like polarity mix readily with one another, which food coloring is more polar (water-based or oil-based)? Which food coloring is less polar (or even nonpolar)? Water-based [Choose ]

Please select the molecule(s) that 1) its molecular shape is different from its electron group shape, and/or 2) the central bonds are not identical. NH3 BF3 PFF PF3

Based on your worksheet results, please match the following: [he molecular shape of NH 3 is [Choose ] [Choose ] [Choose ] [Che molecular shape of BF3 is [Choose] The molecular shape of PF3 is

Based on your worksheet results, please match the following: The electron group geometry of NH 3 is The electron group geometry of BF 3 is [Choose ] The electron group geometry of \( \mathrm{PF5} \) is [Choose ] [Choose ] electron group geometry of SF4 is geometry of PF 3 is [Choose ]