How are planets defined

How do the nuclei of covalently bonded atoms keep the bond together

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

Why is the theory of evolution important? it disproves all other theories about how life began. it provides a topic for debate. it is a unifying concept in biology. it explains how life began. i know for sure, it is not "it is a unifying concept in biology."