Chewing these lightly abrasive, hard foods rubs plaque and stains off the surface of teeth, says Dr. Matthew Messina, a spokesperson for the American Dental Association. Pop a few almonds for a mid-afternoon snackâthey're full of protein, healthy fats, and the crunch you need to get pearly whites. Charles Masters.
As this happened, a cycle of events began to be put into place that causes changes in the rocks that exist on the earth. This cycle is known as the rock cycle. The rock cycle is a model used to describe the creation, alteration, and destruction of the rocks that form from magma. It is important to note that new matter is never created on the earth. All the matter that the earth contains was present when the earth formed and still is here today.
The rock cycle helps to explain how rocks are formed from other rocks. The cycle is shown in the picture below from the U.S. Geological Survey (USGS). You will typically see a picture similar to this one when looking for diagrams of the rock cycle.gneous rocks form when magma or lava cools and hardens into a rock. Magma and lava are rocks that are so hot they move like a liquid. Magma is molten rock that is underground; lava is molten rock that is above the ground â and that is the only difference between them.