Answer:
A. Mafic; iron and/or magnesium
Explanation:
Let's find the answer by naming some minerals and their chemistry.
Mafic minerals are dark-colored whereas felsic minerals are light-colored, thats way mafic rocks are dark-colored because they are mainly composed by mafic minerals and the other way around for felsic rocks.
But remember that mafic minerals as amphiboles, pyroxenes or biotites, involve in their chemical structure iron and/or magnesium. Although calcium and sodium can be incorporated in amphiboles and clinopyroxenes, they are not involved in orthopyroxenes and biotites. On the other hand, although potassium is involved in biotite and in some extent in amphiboles, this element is not involved in pyroxenes.
So in conclusion, mafic minerals are usually dark-colored because they involve iron and/or magnesium in their chemical structures.
Explanation:
The electrons in the outermost electron shell are responsible for forming chemical bonds. These electrons are also known as valence electrons
The molecular weight is between 70 and 85. Let's accidentally pick some quantity in amid, like 78.
7.74% of 78 is how many 'u' there are of H:
78 u * 7.74% = 78 u * .0774 = 6.0372 u
The only hydrocarbon below that has 6 hydrogens is C6H6. We can even check this answer:
Total u = 6C + 6H
= 6(12.01) + 6(1.0079)
= 78.11 u
6(1.0079) / 78.11 * 100 = 7.74%
Answer:
a. The skull could support as much as 3 tons of weight.
Explanation:
The true statement about brain is
a. The skull could support as much as 3 tons of weight.
The cranium(skull) bones are slot like a jigsaw puzzle together. All but one of these bones is fixed in place in adults. It makes the skull very solid. Babies have holes between the cranial (skull) bones so that as they are born, their heads may withstand being crushed.
rest all statements are wrong.
