We did this before and you are right, c is the correct answer.
A is correct for 1 molecule (although some are uncomfortable with the word in this sense---I'm not). So 1 + ion and 1 - ion, such as Na^+ + Cl^- gives only 1 formula unit (1 molecule) of NaCl. The question is asked to make you realize that an ionic solid is an ARRAY of many + and many - ions arranged in a three dimensional network (a lattice). Technically we should write sodium chloride as NaxClx and magnesium chloride as MgxCl2x where x is an indefinite number of these ions. They are equal in number for NaCl but Cl is twice as many as Mg in MgCl2. We don't write NaxClx because that's too much of a hassle. People like me say that NaCl is a molecule; purists will say NaCl is the formula unit. Technically, there is no such thing as a single NaCl unit in real life, partly because we couldn't see it even if it were there. The idea is that when a solution of Na^+ ions and Cl^- ions aggregate, they form that three dimensional lattice. There is no single NaCl "molecule". If you want to go to covalent compounds, you CAN find individual CO2, or CO, or NH3 molecules. There is no network for those gases but there are individual molecules.
What is an ionic solid?
A. One positive ion and one negative ion bonded to form a solid
B. Many nonmetal atoms bonded together to form a solid
C. Many positive and negative ions bonded to form a solid
D. Many metal atoms bonded together to form a solid
I believe the answer is c but answer a is confusing me.
1 answer
1 answer