Today we know volcanoes are openings or vents to the interior of the planet.  About 1,500 volcanoes around the world are considered active, about 90% rest in the Ring of Fire, a band circling the Pacific Ocean.   While the Earth’s surface looks peaceful the crust is made up of slabs of rock that constantly shift, where the plates interact, volcanoes often form.  Friction from shifting plates melts the Earth’s crust, causing rock beneath the crust to liquefy.  This magma then becomes a volcano by erupting through rifts in the plates.  Not all lava is the same.  Volcanoes can be deadly, but it can also be good, it created 80% of Earth’s surface and the air we breathe, rich soil for farming, and some countries harness the heat to create geothermal energy.  Video is very interesting and good quality.  Good for elementary grade and middle school students.