Question

predicting properties based on the periodic table
complete each statement with the word that makes it true.
the noble gases are the least □ of any elements on the periodic table.
the □ form acidic compounds with hydrogen.
the halogens are the most reactive among all the □

Explanation:

1. Noble gases have a full valence electron shell, making them very stable and thus the least reactive elements.
2. Halogens (group 17) react with hydrogen to form acids (e.g., HCl, HBr).
3. Halogens are the most reactive among non - metals due to their high electronegativity and tendency to gain an electron.

Answer:

1. The noble gases are the least \boxed{reactive} of any elements on the periodic table.
2. The \boxed{halogens} form acidic compounds with hydrogen.
3. The halogens are the most reactive among all the \boxed{non - metals}.