What is the mass number of the isotope lithium -7?

What reaction is taking place? 02 + c3h8 = h20 + co2

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

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both