Types of Rocks Worksheet for 6th - 8th Grade | Lesson Planet - Free Printable

Final Answer:
a) (i) Igneous
(ii) Sedimentary
(iii) Metamorphic
b) Magma is molten rock *underground*; lava is magma that has reached the surface.
c) i) Molten rock → cools and solidifies
ii) Coarse-grained → cooled slowly underground (e.g., granite)
iii) Fine-grained → cooled quickly at surface (e.g., basalt)
iv) Intrusive → forms inside Earth (e.g., dike, pluton)
v) Extrusive → forms on surface (e.g., lava flow, volcano)
vi) Obsidian → natural glass, formed from very rapid cooling of felsic lava

──────────────────────────────────────