Obsidian is a type of igneous rock. How do igneous rocks form? from the cooling of magma

from the modification of existing rock

from the cementing of sediments

from the evaporation of waterObsidian is a type of igneous rock. How do igneous rocks form?(1 point)

from the cooling of magma

from the modification of existing rock

from the cementing of sediments

from the evaporation of water

Using this reversible reaction, answer the questions below: n2o4 2no2 (colorless) (reddish-brown) -as the temperature increased, what happened to the n2o4 concentration? -was the formation of reactants or products favored by the addition of heat? -which reaction is exothermic? right to left or left to right? -if the change of enthalpy of this reaction when proceeding left to right is 14 kcal, which chemical equation is correct? n2o4 2no2 + 14 kcal n2o4 2no2, hr = +14 kcal n2o4 + 14 kcal 2no2 n2o4 2no2, hr = -14 kcal