Final answer:
Among the options provided,C- Boron (B) has the least tendency to form a cation due to its atomic structure and it being a non-metal.
Step-by-step explanation:
The element with the least tendency to form a cation among Na, Ca, B, and Al is Boron (B). This is mainly due to the fact that Boron (B) is a non-metal and it has fewer electrons to lose in order to form a cation. Forming cations involves the loss of electrons, something that is easier for metals like Sodium (Na), Calcium (Ca), and Aluminum (Al) due to their atomic structures. However, Boron, being a non-metal, tends to gain or share electrons rather than losing them. Therefore, it has less tendency to form a cation compared to the rest of the options provided.
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