Which would most likely be joined by an ionic bond?

a) a positive metal ion and a positive nonmetal ion

b) a positive metal ion and a negative nonmetal ion

c) a negative metal ion and a positive nonmetal ion

d) a negative metal ion and a negative nonmetal ion

b) a positive metal ion and a negative nonmetal ion.

Because generally ions of non-metal elements (such as the halogens) are negatively charged while ions of metal elements (such as the alkali earth metals) are positively charged. The differences in their changes causes strong electrostatic attraction (an ionic bond).