Answer:
Regional metamorphic rocks form from other rocks (protoliths) by changes in mineralogy and texture in response to changing physical conditions (temperature, lithostatic pressure, and, in most cases, shear stress). Regional metamorphism occurs over broad areas in the lithosphere, possibly influenced by the heat supply. Regional metamorphic rock results from regional metamorphism and usually develops a flaky texture. These changes are essentially solid-state reactions, but very often a fluid phase is present, either participating in the reaction or as a reaction medium. Many regional metamorphic rocks have a chemical composition that is very similar to that of their sedimentary or igneous precursors, with the exception of removal or addition of volatiles (mainly H2O and CO2). This type of behavior is termed isochemical metamorphism. Metamorphism may also take place as a result of a change in chemical environment; this may occur by transport of elements between chemically contrasting rock types (e.g., formation of calc-silicate minerals at a quartzite–marble contact) or by circulation of fluids that dissolve some substances and precipitate others. This process of significant chemical change during metamorphism is known as allo-chemical metamorphism or metasomatism, and rocks formed in this manner are metasomatic rocks. Metasomatism is, however, mostly of local significance, and the total volume of metasomatic rocks in regional metamorphic terranes is rather minor. The distinction between metasomatism and is chemical metamorphism is also a matter of scale. On the scale of individual grains, mass transport takes place during all phase transformations; on the scale of a thin section, it is probably the rule for regional metamorphism; on the scale of a hand (sized) specimen, it can be observed frequently; and on a larger scale, it is the exception.
Hope this Helps!
I think it’s B because I just know
<span>Assume
p=735 Torr
V= 7.6L
R=62.4
T= 295
PV-nRT
(735 Torr)(7.60L)= n (62.4Torr-Litres/mole-K)(295K)
0.30346 moles of NH3
Find moles
0.300L solution of 0.300 M HCL = 0.120 moles of HCL
0.30346 moles of NH3 reacts with 0.120 moles of HCL producing 0.120 moles of NH4+ ION, and leaving 0.18346 mole sof NH3 behind
Find molarity
0.120 moles of NH4+/0.300L = 0.400 M NH4+
0.18346 moles of NH3/0.300L = 0.6115 M NH3
NH4OH --> NH4 & OH-
Kb = [NH4+][OH]/[NH4OH]
1.8 e-5=[0.300][OH-]/[0.6115]
[OH-]=1.6e-5
pOH= 4.79
PH=9.21
.</span>
Troposphere, this is the layer of the atmosphere closest to the earths crust.
Answer:
1: due to difference in reactivity and melting point
2 during the reaction both combine with oxygen in this case magnesium remain solid but some potassium vaporise
