What is the molarity of a solution prepared by dissolving 198 g of BaBr2 in 2.00 liters of solution?

The answer for #3 is c but i don't know why

What is the number of atoms in 3.54 mol s

Rocks, as they are compressed, begin forming mountains above the earth's surface when two continental plates converge. the continental crust increases in depth as the mountains grow above. the himalayan mountains formed at a convergent plate boundary in this manner. the rocks are smashed together causing them to due to the intense heat and pressure from the colliding plates and eventually forming rock. a) melt; igneous b) layer; sedimentary c) recrystallize; metamorphic d) melt into the earth's interior; metamorphic