The quartz in granite begins to melt at 650°C, so if we find a migmatite where quartz has melted in a granitic rock and we know the temperature in the region increased with depth by about 25°C per kilometer, we could estimate the depth that the rock had been at to be about .
a. 12.5 km
b. 18.0 km
c. 23.5 km
d. 26.0 km

d. 26.0 km

Explanation:

If the temperature in the region increases with depth by about 25 °C /km, then at a depth of 2 km the temperature would be 50 °C higher, at a depth of 3 km the temperature would be 75 °C higher and so on.

The only way for finding melted quartz would be if the temperature is at least 650 °C.

We put the data given by the problem and solve for Depth:

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

answer: mole of the gas

answer: mole of the gasexplanation: