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.
Hello!
During the Great Depression, it was difficult for all races/social classes to find work. Unemployment rates were high and the economy was close to collapsing. Although all races and genders had a hard time finding work, unemployment rates for African Americans were higher than unemployment rates for whites. African Americans were discriminated against and their unemployment rate was nearly 20% higher than white workers.
The correct answer to your question is D: Unemployment rates among African Americans were higher than unemployment rates among whites.
I hope this answers your question!
Answer:
Answer : Pope Urban ll
Explanation: He is best known for initiating the Crusades.
The meaning of initiating is
cause (a process or action) to begin.
So the answer is Pop Urban ll
Answer:
"That the 1912 election registered, and inspired, fundamental changes in American politics suggests the historical significance of the Progressive Party. Not only was it the driving force of this election, but it remains the most important third party to appear on the American political landscape in the 20th century."
Explanation:
The fifteenth amendment. It gave ALL citizens the right to vote
