How is a compound different from a mixture? *

a. mixtures are created through physical changes; compounds are created through chemical reactions.
b. compounds are created through physical changes; mixtures are created through chemical reactions.
c. mixtures, on average, are heavier than compounds.
d. compounds, on average, are heavier than mixtures.

a.  mixtures are created through physical changes and compounds are created through chemical reactions

Explanation:

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.

i don't know people like to fight everywhere rip.