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.
The disadvantage of sexual reproduction is that outside influences can determine the viability of the offspring. In humans, for example, a failure for a mother to consume an adequate amount of folic acid is directly linked to neural tube birth defects. This defect occurs at the earliest stages of development, often when a woman doesn’t know she is pregnant, which means the folic acid must be consumed when attempting to conceive.
From the information give, I'm going to assume the wave is in a vacuum...
You use the equation: f=

where c is the constant for speed of light (

so f=

f= 4.89 x

Hz (approximately)
Answer:
the nucleus of the atom was centrally located i n the atom and was positively charged
Explanation:t
False, it is an example of an Ionic solid