Which of the following is an example of a body-centered cubic cell?

At room temperatures, elements lithium, sodium, rubidium, barium, vanadium, chromium and iron have structures that can be described as a body center cubic packing of spheres. The packing fraction of a body center cubic cell is 0.68.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.