Answer:

Explanation:
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In this case, for such formation of sulfur hexafluoride, the standard enthalpy of formation is -1220.47 kJ/mol (data extracted from NIST database). Next, we compute the moles in 10.0 grams of sulfur hexafluoride as shown below:

Next, for the given energy, we compute the total heat that is liberated:

Finally, we conclude such symbol has sense since negative heat is related with liberated heat.
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The arrangement of electron pairs around CH4 and NH3, According to the VSEPR model is the same, because in each case there are the same number of electron pairs around the central atom. So the NH3 and CH4 arrangement of electron pairs is the same because in each case there are the same number of electron pairs around the central atom.
'Every action has an equal but opposite reaction' They are equal, but opposite.
Increased upwelling in a coastal area results to more aquatic life. Upwelling is the process in which deep, cold water rises towards the surface. It is an oceanographic phenomenon that involves wind driven motion of the dense, cooler and usually nutrient-rich water towards the ocean surface replacing the warmer usually nutrient depleted surface water.