Which statement correctly describes a physical change?

involves breaking and creating chemical bonds but not changing a phase

may involve a change in phase but does not involve a change in the molecular structure

may involve converting two or more substances into new substances

involves changes at the molecular level

involves energy transfer and change in color

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.