Final answer:
The element with properties of metals and nonmetals, 5 valence electrons, and an atomic number higher than tin (50) is antimony (Sb) from the pnictogens group with an atomic number of 51 and classified as a metalloid.
Step-by-step explanation:
The element you are describing should have properties of both metals and nonmetals, possess 5 valence electrons, and have an atomic number higher than tin (Sn). Tin has the atomic number 50. An element with these characteristics is classified as a metalloid or semimetal, and belongs to group 15 of the periodic table, known as the pnictogens. The pnictogens with atomic numbers higher than tin include antimony (Sb, atomic number 51), tellurium (Te, atomic number 52), and polonium (Po, atomic number 84). Antimony and tellurium are typically recognized as metalloids, with characteristics of both metals and nonmetals. However, only antimony has 5 valence electrons, corresponding to the valence electron configuration of the pnictogens.