Question

read the next section of the openstax reading before answering the question on the right. what is true of naming molecular compounds composed of two elements? when an element has more than one atom, it must get a prefix to specify how many atoms it has. numbers are irrelevant when naming molecular compounds. the last element always ends in -ide. when the first element has only one atom, it does not need a prefix. the first element ends in -ide.

Explanation:

• For naming molecular compounds composed of two elements:
• Prefixes are used to specify the number of atoms when an element has more than one atom (e.g., \(CO_2\) is carbon dioxide, where "di -" indicates two oxygen atoms). So the statement "When an element has more than one atom, it must get a prefix to specify how many atoms it has" is correct.
• Numbers (represented by prefixes) are relevant in naming molecular compounds. So the statement "Numbers are irrelevant when naming molecular compounds" is incorrect.
• In binary molecular compounds (compounds with two elements), the second (last) element in the formula has its name changed to end in -ide (e.g., in \(H_2O\), oxygen is named oxide). So the statement "The last element always ends in -ide" is correct.
• When the first element has only one atom, the prefix "mono -" is usually omitted (e.g., \(CO\) is carbon monoxide, not monocarbon monoxide). So the statement "When the first element has only one atom, it does not need a prefix" is correct.
• The first element does not end in -ide. The second (last) element ends in -ide. So the statement "The first element ends in -ide" is incorrect.

Answer:

• When an element has more than one atom, it must get a prefix to specify how many atoms it has.
• The last element always ends in -ide.
• When the first element has only one atom, it does not need a prefix.