Question

1. what effect does a fast cooling rate have on grain size in igneous rocks? a. it forms fine - grained crystals. b. it forms large - grained crystals. c. it forms light crystals. d. it forms dark crystals.

Explanation:

In igneous rocks, a fast - cooling rate means there is less time for atoms to arrange into large crystals. So, fine - grained crystals form.

Answer:

A. It forms fine - grained crystals.