Please help me figure out B on Example E where the red pen is. :)

Complete the sentence to describe the law of conservation of energy. the law of conservation of energy states that energy cannot be created

Consider a u-tube whose arms are open to the atmosphere. now equal volumes of water and light oil (ρ = 49.3 lbm/ft3) are poured from different arms. a person blows from the oil side of the u-tube until the contact surface of the two fluids moves to the bottom of the u-tube, and therefore, the liquid levels in the two arms are the same. if the fluid height in each arm is 30 in, determine the gage pressure exerted by the person on the oil by blowing.

Why do metals "give up" their valence electrons?