Question

In covalent compounds with nonmetals, hydrogen is assigned an oxidation number of 1 +.

The exception to this rule is when hydrogen combines with a metal to form a hydride. Under these conditions, which are rare, hydrogen is assigned an oxidation number of 1-.
What is the oxidation number of hydrogen in covalent compounds with nonmetals, and what is the exception to this rule?
A) Hydrogen is assigned an oxidation number of 1+ in covalent compounds with nonmetals, and 1- when it combines with a metal to form a hydride.
B) Hydrogen is assigned an oxidation number of 2+ in covalent compounds with nonmetals, and 1- when it combines with a metal to form a hydride.
C) Hydrogen is assigned an oxidation number of 1+ in all compounds.
D) Hydrogen is assigned an oxidation number of 1- in covalent compounds with nonmetals, and 1+ when it combines with a metal to form a hydride.

Answer 1

The oxidation number of hydrogen is +1 when combined with nonmetals in covalent compounds and -1 when it forms a hydride with metals.

Step-by-step explanation:

The oxidation number of hydrogen in covalent compounds with nonmetals is +1. There is an exception to this rule when hydrogen combines with a metal to form a hydride, under these special conditions, the oxidation number of hydrogen is -1. This is because in a hydride, hydrogen gains an electron from the metal, thereby having characteristics similar to halides.

Thus, the correct answer to the question is A) Hydrogen is assigned an oxidation number of 1+ in covalent compounds with nonmetals, and 1- when it combines with a metal to form a hydride.