Question

ionic compounds
take a moment here to reflect on the composition of each of the molecules in the table entitled names of some ionic compounds. then, answer the question on the right.
which of the following is true about all of the molecules named in this way?
they all consist of only two elements.
the first element is a metal, and the second is a nonmetal.
the number of atoms belonging to either element is not reflected in the compounds name.
the name of the metal ion gets an -ide suffix added to it.
the name of the nonmetal ion gets an -ide suffix added to it.

Explanation:

• Option 1: Ionic compounds can have more than two elements (e.g., \(Na_2SO_4\) has three elements - Na, S, O). So, this option is incorrect.
• Option 2: In ionic compounds, the first element (cation) is usually a metal (loses electrons to form positive ion) and the second (anion) is a non - metal (gains electrons to form negative ion). For example, in \(NaCl\) (sodium chloride), \(Na\) (metal) and \(Cl\) (non - metal). This option is correct.
• Option 3: In the naming of simple ionic compounds like \(NaCl\) (sodium chloride), the number of atoms (\(1:1\) ratio here) is not indicated in the name. But for compounds like \(Fe_2O_3\) (iron(III) oxide), the charge of the metal (which can be related to the ratio in simple cases) is indicated. However, in general, for simple binary ionic compounds (two - element ionic compounds), the number of atoms is not reflected in the name. For example, \(MgO\) (magnesium oxide, \(1:1\) ratio) and \(Al_2O_3\) (aluminium oxide, \(2:3\) ratio) - the ratio is not in the name. This option is correct.
• Option 4: The suffix “-ide” is added to the non - metal ion. For example, in \(NaCl\), the non - metal \(Cl\) becomes “chloride”. So, this option is incorrect.
• Option 5: As explained in the case of \(NaCl\) (chloride), the non - metal ion gets the “-ide” suffix. For example, \(S^{2 - }\) becomes “sulfide” in \(Na_2S\) (sodium sulfide). This option is correct.

Answer:

The first element is a metal, and the second is a nonmetal; The number of atoms belonging to either element is not reflected in the compound’s name; The name of the nonmetal ion gets an -ide suffix added to it.