On the basis of electronegativity, which pair of elements is most likely to form a polyatomic ion?

a. cs and cl

b. ba and o

c. o and p < -- i believe this is correct.

d. na and br

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?