The answer is; C
In folding, when segments of Earth's crust are bent and doubled over, the sediments in between are form folds, since they are forced into a smaller space. This also occurs in converging plates boundaries.
Block Mountains occur when stress due to compression in the crust causes the hanging wall between a fault to move up relative to the footwall.
Answer: An atom can be considered unstable in one of two ways. If it picks up or loses an electron, it becomes electrically charged and highly reactive. Such electrically charged atoms are known as ions. Instability can also occur in the nucleus when the number of protons and neutrons is unbalanced.
Explanation:
Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms, and because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules.