Scientists estimate earth's age to be 4.6 billion years. samarium has a half-life of approximately 106 billion years. from the present date, approximately how many more years must pass before a sample of samarium that was created at the beginning of earth's history contains 25 percent of the original parent material? 10 billion 26 billion 100 billion 206 billion

Which of the following might a chemist choose to study? a. glacier movement in alaska b. better ways to recycle plastics c. the effects of hurricanes on turtle populations d. the vibrations in bridges caused by big trucks

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

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