<span>inorganic
Let's look at the choices and see why they work, or don't work.
monosaccharide
* Otherwise known as a simple sugar. And NaCl is definitely not a sugar of any type. So this is wrong.
disaccharide
* Complex sugar. And NaCl doesn't qualify either.
organic
* A definition of an organic compound is one that has carbon in it. NaCl has sodium and chlorine. No carbon at all, so this isn't the right answer. And I wish that organic was an earlier choice, since the sugars mentioned above are organic compounds.
inorganic
* This is the only possible choice. Salt is not an organic compound since it doesn't have carbon. So it can't be a sugar either. But it can and is inorganic.</span>
fourth period
The third period is similar to the second, except the 3s and 3p sublevels are being filled. Because the 3d sublevel does not fill until after the 4s sublevel, the fourth period contains 18 elements, due to the 10 additional electrons that can be accommodated by the 3d orbitals.
