Select all cases in which the units comprising the solid are best classified as molecules.
ScBr3
Fe
IF
H2S
IF5
Kr
None
The question is a little confusing to me. I suppose Fe, IF, Kr, and IF5 are covalent compounds and would be classified as molecules. ScBr3 probably is more ionic and not classified as molecules but as ions. H2S is primarily covalent; as a gas it surely must be covalent and molecular but as a solution it does ionize slightly.
To determine which cases can be classified as molecules, we need to first understand what a molecule is.
A molecule is a combination of two or more atoms that are chemically bonded together. These atoms can be of the same element (in the case of diatomic molecules) or different elements (in the case of compound molecules).
Let's analyze each option and determine if it can be classified as a molecule:
1. ScBr3: Scandium bromide (ScBr3) is a chemical compound consisting of one scandium atom and three bromine atoms. Thus, it can be classified as a molecule.
2. Fe: Iron (Fe) exists naturally as individual atoms and is not chemically bonded to form a molecule. Therefore, it is not classified as a molecule.
3. IF: Iodine fluoride (IF) is a chemical compound consisting of one iodine atom and one fluorine atom. It can be classified as a molecule.
4. H2S: Hydrogen sulfide (H2S) is a compound consisting of two hydrogen atoms bonded to one sulfur atom. Hence, it is a molecule.
5. IF5: Iodine pentafluoride (IF5) is a compound consisting of one iodine atom and five fluorine atoms. Therefore, it is a molecule.
6. Kr: Krypton (Kr) is a noble gas that exists as individual atoms and is not chemically bonded to form a molecule. Hence, it is not classified as a molecule.
Based on our analysis, the cases in which the units comprising the solid are best classified as molecules are:
- ScBr3
- IF
- H2S
- IF5
Therefore, the answer is: ScBr3, IF, H2S, and IF5.