1. What is the difference between between magma and lava?
   
   Magma is molten rock from deep within the Earth (the mantle). Lava is the name given to this molten rock when it reaches the Earth’s surface.
2. Label the indicated parts of the volcano.

1. summit crater
2. subsidiary vent
3. main vent
4. sill
5. dike
6. magma chamber

3. List two kinds of tectonic plate motion that may result in volcanoes.
   
   Convergent plates (plates colliding or coming together), and divergent plates (plates pulling apart) may result in volcanoes.
4. Distinguish between the formation of volcanoes formed on a continent’s edge, and the formation of island arcs.
   
   Both types of volcanoes are formed by convergent plates interacting. Volcanoes on a continent’s edge are formed by oceanic crust colliding with continental crust. Island arcs are formed by two plates of oceanic crust colliding.
5. How do geologists explain the formation of volcanoes far from any plate boundary?
   
   These volcanoes are formed by hot spots. Hot spots are stationary plumes of magma that form volcanoes as a tectonic plate slowly drifts by above the hot spot.