AP BIOLOGY

Detailed explanation-1: -The octet rule is only applicable to the main group elements. The molecules of the halogens, oxygen, nitrogen, and carbon are known to obey the octet rule. In general, the elements that obey this rule include the s-block elements and the p-block elements (except hydrogen, helium, and lithium).

Detailed explanation-2: -The hydrogen valence electrons act like helium, element number 2. There is 1 hydrogen valence electron and H forms 1 bond. The simple logic is that 1 + 1 = 2 for hydrogen. Helium and hydrogen are exceptions to the octet rule, and some say the “duet rule” applies.

Detailed explanation-3: -While most atoms obey the duet and octet rules, there are some exceptions. For example, elements such as boron or beryllium often form compounds in which the central atom is surrounded by fewer than eight electrons (e.g., BF₃ or BeH₂).

Detailed explanation-4: -1. What elements can be an exception to the octet rule? There aren’t enough electrons in hydrogen, beryllium, or boron to make an octet. There is only one valence electron in hydrogen, and there is only one site for it to make a connection with another atom.

Detailed explanation-5: -Hydrogen is an exception to the octet rule. H forms only one bond because it needs only two electrons.