The oxidation number of all metals on the periodic table have a positive (+) charge. Which of these BEST explains why?
A) Metals are known to add protons to their nuclei causing them to become positively charged.
B) All metals lose one or more valence electrons to become stable, giving them a positive oxidation number.
C) All metals gain one or more valence electrons to become stable, giving them a positive oxidation number.
D) Metals are known to lose protons and add neutrons to their nuclei causing them to become positively charged.

Option B) All metals lose one or more valence electrons to become stable, giving them a positive oxidation number.

Explanation:

Yes! metals such as cadmium, sodium, aluminum etc all lose their outermost electrons to nonmetals in chemical reactions to become stable (having an octet or duplet structure), and forming a positively charged ion.

For instance: To form sodium chloride, NaCl Sodium Na, loses its single outermost electron to Chlorine

Na --> Na+ + e-

Thus, Na+ means sodium has a positive oxidation number of +1, and is with a octet stable structure of (2,8) instead of (2,8,1)