13. weathering is the breakdown of rock through mechanical disintegration and physical stress.

14. water, wind, and ice are forces that act on rocks in the rock cycle.

15. mechanical weathering does not change the of rocks.

16. observing the ­ of a mineral is a reliable way to identify it.
17. is the source of heat and pressure required to create metamorphic rocks.
18. mechanical weathering breaks rocks into smaller pieces without changing them, while chemical weathering changes the of rocks.
19. the layers or banding of some metamorphic rocks is called
20. the type of sedimentary rock formed from fragments of minerals or rocks is fill in the blanks