Mafic magmas may contain up to about 75 percent SiO2 by weight. are viscous and do not flow easily. tend to inhibit passage of gas that tries to escape through it. result in less violent eruptions than felsic to intermediate magmas.

result in less violent eruptions than felsic to intermediate magmas.

Explanation:

Mafic magma results in less violent eruptions than felsic to intermediate magma.

They are predominantly made up of a high level of magnesium and iron in their composition.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

the answer is c. nacl