Which evidence recorded at seismic stations following an earthquake supports the inference that earth’s interior changes from solid rock to molten iron and nickel at the mantle-core boundary?

During an earthquake, waves radiate out spherically from the epicenter and reach the surface. There is usually a shadow zone on the earth's surface approximately 104 to 140 degrees of angular distance above the epicenter of the earthquake where no waves are recorded by seismographs. This is because P-waves are refracted by a liquid medium during transmission in the liquid outer core while S-waves cannot transmit through a liquid medium. This means that the interior outer core of the earth is molten.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.