C, erosion. Erosion is the natural process of breaking down natural products through wind, or similar natural resources.
Substances that are not chemically bonded are mixtures.
The answer is B. Equilibrium means a state in which opposing forces or influences are balanced.
Valency- it means the combing capacity if an element.
<span> radical- it is an atom, molecule, or ion that has unpaired valence electrons or an open electron shell.
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