Which diagram shows a pair of electrons that have opposite spins?

How can one make a supersaturated solution? (apex)

Which statement names the physical property of wood a. wood is softer than coal b. wood does not rust c. wood can rot d. wood can burn

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world