Final answer:
The element with the least metallic character is found at the top right of the periodic table; Helium, a noble gas with a complete valence shell, is typically the most nonmetallic and so has the least metallic character.
Step-by-step explanation:
Metallic Character and Its Periodic Trends
- When discussing which element has the least metallic character, we refer to the element's inability to easily lose valence electrons. Factors affecting metallic character include atomic size, ionization energy, and electron affinity. The periodic trend shows that metallic character increases from top to bottom within a group due to increased atomic size and decreased nuclear pull on the valence electrons, making them easier to remove. Conversely, the metallic character decreases from left to right across a period because atomic size decreases and valence electrons are more tightly held.
- Conductivity and malleability are properties related to metallic character as these require easily removable electrons. It is also important to note that there is no clear division between metallic and nonmetallic character; elements gradually change from metallic to nonmetallic across the periodic table. The nonmetallic character is associated with elements that readily accept electrons to form anions.
- Given this understanding of periodic trends, we can deduce the elements with the least metallic character are found at the top right of the periodic table, such as the noble gases or highly electronegative elements like fluorine. However, to answer specifically which element has the least metallic character, one would look for the most nonmetallic, which is typically Helium, belonging to the noble gases with a complete valence shell rendering it virtually unreactive and nonmetallic.