¿a que se denomina espacio ártico?

The earth is composed of three different chemical layers: core, mantle and crust. the formation of these layers was from a process called

What are the answers for the following questions?

You have been tasked with sorting the rock samples shown into three categories, with two rocks in each category. what attribute would you use to sort these rocks? which rocks would be in each category? rocks: obsidian, coquina limestone, granite, soapstone, pumice, and gneiss.