Question

what is the difference between intrusive rocks and extrusive rocks

Answer 1

the major visible difference between the two are crystal size, intrusive rocks have a larger crystal/grain texture due to the slow cooling of magma below the earth surface which encourages the growth of larger crystals, while extrusive rocks, because of the rapid cooling at/above the earth's surface does the opposite

Answer 2

Intrusive rocks are formed when magma cools on the inside of the earths surface while extrusive rocks form when lava cools on the outside of the earths surface.