What combines to form compounds? a. atoms of elements b. molecules c. minerals d. valences

1 a

2 d

3 a

4 c

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.