Answer:
The correct answer is:
<em>(1) It is important that the sample is dissolved in just enough hot solvent. </em>
Explanation:
The process of recrystallization is important to eliminate the impurities and to obtain better crystals of the solid. The solvent used to perform the recrystallization must have a high dissolution power of the substance to be recrystallized and a low dissolution power of the impurities. This is in order to eliminate most impurities. Furthermore, <em>It is important that the sample is dissolved in just enough hot solvent </em>because this should be easy to remove after the recrystallization and the crystal should form easily when the solution cools. Also, it is better to add the hot solvent to solubilize the crystals and keep the impurities insoluble, instead of adding the cold solvent and heating the solution. Additionally, the process of cooling the solution must be done slowly to obtain large and fewer crystals. A fast ice-cooling will form smaller crystals.
Answer:
Hornfels most commonly form in the aureole of granitic intrusions in the upper or middle crust. Hornfels formed from contact metamorphism by volcanic activity very close to the surface can produce unusual and distinctive minerals.
The definition of a gem is "a precious stone, cut and polished for jewelry. They are all minerals. Some highly desirable gemstones may not be suitable for jewelry, yet be very collectible, like sphene. Others, like those in the corundum family, are prized for color and hardness, like emeralds and diamonds. Further, some common minerals, when polished, make beautiful pieces. With all that said, i woukd go with rarer.
Answer:
It demonstrates that it a physical change because you can't see nothing happening but something happening
Sry if it doesn't make sense
