Oceanic crust<span>tends to be denser and thinner than </span>continental crust<span>, so the denser </span>oceanic crust<span> gets bent and pulled under, or subducted, beneath the lighter and thicker </span>continental crust<span>. This forms what is called a subduction zone. The answer is B.</span>
An atom will usually form either an ionic bond or covalent bond with another atom but not both.
Ionic bonds are the kind of bonds that result when one atom transfers or gives up electrons and another atom receives them and adds them to its own energy shells.
An example is sodium metal and chlorine gas. Sodium gives up two of its electrons and Chlorine receives them and the two elements form an ionic bond to create sodium chloride, a new compound.
Covalent bonds are the kind of bonds formed when two atoms decide to share electrons. No atom gives up any electrons and neither does the other atom receive any. An example is water. An oxygen atom shares two of its electrons with two hydrogen atoms to form a molecule of water (H2O).
