Which of the following is the most common oxidation number for group 15 elements in their compounds?

• A. -3
• B. +2
• C. 0
• D. +5

Answer: (A)

Verified step by step guidance

1. Identify the group 15 elements in the periodic table, which include nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).
2. Recall that group 15 elements have five valence electrons, as their outer electron configuration is typically ns\^2 np\^3.
3. Understand that these elements can either gain three electrons to complete their octet, resulting in an oxidation state of -3, or lose five electrons to reach a noble gas configuration, resulting in an oxidation state of +5.
4. Consider the common oxidation states observed in compounds: the -3 oxidation state is very common because these elements tend to gain three electrons to fill their valence shell, especially for lighter elements like nitrogen and phosphorus.
5. Conclude that the most common oxidation number for group 15 elements in their compounds is -3, as it corresponds to the stable electron configuration achieved by gaining three electrons.