Answer:
Mohs hardness, rough measure of the resistance of a smooth surface to scratching or abrasion, expressed in terms of a scale devised (1812) by the German mineralogist Friedrich Mohs. The Mohs hardness of a mineral is determined by observing whether its surface is scratched by a substance of known or defined hardness.
Related Topics: hardness
To give numerical values to this physical property, minerals are ranked along the Mohs scale, which is composed of 10 minerals that have been given arbitrary hardness values. The minerals contained in the scale are shown in the Table; also shown are other materials that approximate the hardness of some of the minerals. As is indicated by the ranking in the scale, if a mineral is scratched by orthoclase but not by apatite, its Mohs hardness is between 5 and 6. In the determination procedure it is necessary to be certain that a scratch is actually made and not just a “chalk” mark that will rub off. If the species being tested is fine-grained, friable, or pulverulent, the test may only loosen grains without testing individual mineral surfaces; thus, certain textures or aggregate forms may hinder or prevent a true hardness determination. For this reason the Mohs test, while greatly facilitating the identification of minerals in the field, is not suitable for accurately gauging the hardness of industrial materials such as steel or ceramics. (For these materials a more precise measure is to be found in the Vickers hardness or Knoop hardness) Another disadvantage of the Mohs scale is that it is not linear; that is, each increment of one in the scale does not indicate a proportional increase in hardness. For instance, the progression from calcite to fluorite (from 3 to 4 on the Mohs scale) reflects an increase in hardness of approximately 25 percent; the progression from corundum to diamond, on the other hand (9 to 10 on the Mohs scale), reflects a hardness increase of more than 300 percent.
Brown V. Board of Education was a landmark decision enacted by the US Supreme Court in 1954, that abolished segregation in public schools and understood that the 'separate but equal' principle that had governed such procedures was violating the Equal Protection Clause and therefore, unconstitutional. This clause was introduced by the 14th amendtment to the US Constitution during the Reconstruction Era, aiming to guarantee equality of rights to all US citizens.
This decision in 1954 overturned the former Plessy v. Ferguson decision from 1896, that had understood that the 'separate but equal' principle did not violate the Equal Protection clause and therefore it enabled segregation.
It Demonstrates the Importance of Trade.
The executive order 0970 or something I think
Most of the work are done in the committees.
<u>Explanation: </u>
A congressional committee is defined as a legislative sub-organization for the "United States Congress". In a general Congress, it is expected that no one member is all knowing. Thus, the presence of these Congressional committees provides incomparable and invaluable informational services for the Congress by compiling information and reporting back to the Congress on specialized subject matters.
This investigatory functioning part of the Congress is non-replaceable, and certainly has more work done than the debate floor, Senate or the House of Representatives. Thus, making the answer in the committees correct.
