What elements do living things have that volcanic rocks do not have? Oxygen, Silicon, Magnesium or Carbon

I believe it is Silicon.

Explanation:

From my research, I know that volcanic rocks have carbon, oxygen, and magnesium. I read that traces of silicon have been found in animal bones.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called