What can a drop of liquid mercury be described as?
a) a pure substance and a compound
b) an impure substance that is reactive
c) an impure substance that is unreactive
d) a pure substance and an element

D) a pure substance and an element

Explanation:

Mercury is an element which is composed of similar atoms and is a pure substance.

Element is a pure substance which is composed of atoms of similar elements.

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

Mixtures are impure substances and are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.

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.