arbon, as with many elements, can arrange its atoms into several different geometries, or "allotropes." In pure diamond, every carbon atom is covalently bonded to exactly 4 other carbon atoms in a very specific and energetically favorable geometry. The diamond cannot be broken or scratched unless many covalent bonds are broken, which is difficult to do. In another common allotrope, graphite, every carbon atom is covalently bonded to only 3 other carbon atoms, and the atoms are arranged in sheets that are not covalently bonded to each other. The sheets can be broken apart easily, ultimately meaning that graphite can be easily scratched. Coal is composed of particles of different allotropes of carbon, and some "amorphous carbon," which has no defined geometry in its atomic structure. Without a continuous network of covalent bonds, coal is easily scratched (i.e. it is not hard).
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Explanation:
Loess is a sediment that is formed from silt deposits due to wind. The composition of the silt is clay and sand. The components are cemented together by calcium carbonate. The silts are blown by wind and accumulate in a singular location.
Answer:
Pressure is simply the force experienced by an object divided by the area of the surface on which the force acts. Note that the force here is the force acting perpendicular to the surface. The unit for pressure is the pascal, Pa.
Explanation:
STEP ONE: Harvesting Radiant Energy
The first step of photosynthesis occurs in the chloroplasts of plant cells. Light photons are absorbed by a pigment called chlorophyll, which is abundant in the thylakoid membrane of each chloroplast. Chlorophyll appears green to the eye because it does not absorb green waves on the light spectrum. It reflects them instead, so that’s the color you see.
STAGE 2: Converting Radiant Energy
After radiant energy from sunlight is absorbed, the plant converts light energy into a usable form of chemical energy to fuel the plant’s cells
STAGE 3: Storing Radiant Energy
The last stage of the photosynthesis process is known as the Calvin-Benson cycle, in which the plant uses atmospheric carbon dioxide and water from soil to convert ATP and NADPH. The chemical reactions that make up the Calvin-Benson cycle occur in the stroma of the chloroplast.