I think you mean ionic bond and not conic bond. The pair of elements that form an ionic bond are barium and chlorine.
Answer:
A. tungsten
Explanation:
Tungsten is a material which high melting point ie. does not melt easily incase of high temperature
Answer: B or C
Explanation: The question does not include the variable or steps Brian is using so either one could be correct. It has to be the one that he is controlling though. This is because a control group is used to rule out any alternate explanations. Therefore the answer should be the one that he is trying to test out.
