The boiling point of liquid oxygen is 90.2 k at atmospheric pressure. (a) what is this temperature on the celsius scale?

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

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

Ineed ! i have no clue how to do this problem.