Question

1. what characteristic was most useful in identifying each type of rock listed below? explain.

a. igneous -
b. metamorphic -
c. sedimentary -

Explanation:

a. Igneous rocks are best identified by their texture and crystal - size, which are determined by the cooling rate of magma or lava. Rapid cooling leads to small crystals or a glassy texture, while slow cooling results in large crystals.
b. Metamorphic rocks are often identified by their foliation (layering) or lack thereof, as well as the presence of metamorphic minerals formed under high - pressure and high - temperature conditions.
c. Sedimentary rocks are typically recognized by their bedding (layering) and the presence of fossils, which are remnants of past life forms that got trapped during sediment deposition.

Answer:

a. Texture and crystal - size. The cooling rate of magma/lava affects these features.
b. Foliation and metamorphic minerals. Formed under high - pressure and high - temperature.
c. Bedding and fossils. Result of sediment deposition and past life forms.