1. Problem: We have three consecutive elements K, L, and M in a section of the periodic table, and one of them is a metalloid (yarımetal). We want to determine which of the given information types (I. group numbers, II. atomic numbers, III. period numbers) alone or combined can identify the metalloid element. 2. Important concepts: - Group number: Vertical column in the periodic table; elements in the same group have similar properties. - Atomic number: Unique number of protons; strictly increases by 1 for consecutive elements. - Period number: Horizontal row in the periodic table. 3. Analysis: - Knowing only the group number (I) is not enough because consecutive elements K, L, M have consecutive atomic numbers but may belong to different groups. - Knowing only the atomic number (II) identifies the element uniquely, so it is sufficient to know which is the metalloid. - Knowing only the period number (III) is not enough because consecutive elements can be in the same period or different periods. 4. Combining information: - I and II: Since II alone is sufficient, adding I is redundant. - II and III: II alone is sufficient, so adding III is redundant. 5. Conclusion: Only knowing the atomic number (II) alone is sufficient to identify the metalloid element among K, L, and M. Answer: B) Yalnız II