I am no expert but I think the correct answer is C.
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).
The correct answer is option A, that is, a landfill in the region of nonporous bedrock.
A permanent waste disposal facility where the wastes are put into the ground and covered with a layer of plastic, soil, or both is known a landfill. A secure chemical landfill refers to a landfill developed in the region of nonporous bedrock.
A secure chemical landfill is a prudently engineered depression in the ground or constructed on the top of the ground, signifying a football stadium into which wastes are dumped. The objective is to inhibit any water-related or hydraulic association between the surrounding environment and the wastes, mainly groundwater.
The Foramen (Meaning Opening) Magnum (Meaning Large) is a large opening at the base of the skull that the spinal cord passes through to connect the lower body to the brain. The Foramen Magnum is<span> one of the several foramina found in the base of the skull.</span>
