Since we know the percentages by mass, we can convert them into grams by imagining a 100-gram sample of the mystery compound. At that point, we can determine how many moles are present for each element:

By dividing each molar amount by the smallest molar amount (in this case 3.33), we can find the elemental ratios.

This means that the empirical formula for this compound is .

Since we were told that the molecular formula is six times as heavy as the empirical formula, we need to multiply each elemental amount in the empirical formula by six. After doing this, we find that the molecular formula is .

Carboxylic acids are formed by a carbon atom with a double bond to an oxygen atom, as well as an -oh substituent. This leaves one remaining bond for the carbon atom, allowing it to bind to a larger molecular component. The name for a carboxylic acid bound to a larger molecule is a "carboxyl group."

Carbonyl groups are formed when a carbon atom forms a doubl bond with an oxygen atom and any two other substituents. Carboxylic acids, aldehydes, ketones, esters, and amides are all carbonyl functional groups.

An ester is formed when a carbon forms a double bond with an oxygen and a single bond with a second oxygen atom. The second oxygen is generally incorporated into the backbone structure of the molecule, rather than as a single substituent to the carbon.

An ether is formed by an oxygen atom bound to two other atoms (usually carbons).

Ionic bonds generally occur between metal and nonmetal ions, while covalent bonds usually occur between two nonmetal atoms. The compounds containing sodium, iron, silver, calcium, and rubidium will all contain ionic bonds involving these elements.

The answer  is the only answer without any metal atoms, indicating that the bonds in these molecules will be covalent.

Hydrogen bonds are present in molecules in which hydrogen atoms are bound to highly electronegative atoms, namely oxygen, fluorine, or nitrogen. These bonds are extremely polar, resulting in a partial positive charge on the hydrogen atoms and a partial negative charge on the more electronegative atom.

Of the given answer options, methane (), is the only one that does not involve a hydrogen atom bound to an oxygen, nitrogen, or fluorine. It cannot demonstrate hydrogen bonding.

Note that glucose (), as well as most other sugars, contain aldehyde or hydroxyl groups. These consist of -OH bonds, which allow for hydrogen bonding.

Electronegativity is defined as the tendency of an atom to attract an electron in a bond that it shares with another atom. Because oxygen wants to receive two elctrons, while both sodiums wish to lose one electron, oxygen has a higher electronegativity than sodium. Typically, electronegativity can be seen as increasing as you go to the top right of the periodic table. For example, fluorine has a higher electronegativity than nitrogen.

Ionic bonds most commonly form between metals and non-metals. Non-metals have high electronegativities and metals have low electronegativities. In these type of bonds, electrons are transferred from the metal to the non-metal because of the large difference in electronegativities. The non-metal will try to gain an electron (high electronegativity) and the metal will try to donate an electron (low electronegativity). The result is a complete electron transfer, known as an ionic bond.

Electronegativity is the tendency of an atom to attract an electron. Elements with very high electronegativities are found at the upper right of the periodic table, while those with low electronegativities are found at the lower left. When two atoms have a very large difference in electronegativity, one atom will have a much greater tendency to attract an electron than the other. As a result, the more electronegative element will pull an electron away from the less electronegative element, creating an electron transfer. This transfer is an ionic bond.

Most non-metals have very high electronegativities, while most metals have very low electronegativities. This is why ionic bonds usually form between a metal atom and a non-metal atom.

There are two primary types of intramolecular bonds: ionic bonds and covalent bonds. In an ionic bond, an electron is transferred (donated) from one atom to the other, usually allowing both atoms to satisfy the octet rule. In a covalent bond, electrons are shared between two atoms in order to allow both to satisfy the octet rule.

Ionic bonds usually form between a metal and a non-metal. HCl, NaCl, and NaOH are all examples of molecules that contain ionic bonds.

Ionic bonds occur when there is a large electronegativity difference between two atoms, such as elemental between fluorine and potassium. The transfer of one electron will fill the valence electron shell of both atoms. Remember that ionic bonds result in ions, or charged species. A covalent bond is a chemical bond in which two atoms share one or more electrons, but the electron(s) is/are never fully donated or accepted.

An ionic bond is a complete transfer of electrons between atoms which forms a cation and an anion. A metal (cation) tends to gain electron(s) and a non-metal tends to lose electron(s). Both act to satisfy their octets and the electrostatic attraction between the oppositely charged atoms holds them together.

Diatomic chlorine forms covalent bonds since they are equal in terms of electronegativities.

 forms a polar covalent bond based on the two atom's differing electronegativities, and on the fact that both atoms are nonmetals.

 has both ionic bonds (between the metal  and polyatomic ion) and covalent bonds within the polyatomic ion. Since we are only looking for ionic bonds,  is the correct answer.