Elements with valency 1 are:(i) Always metals. (ii) Always metalloids.(iii) Either metals or non-metals. (iv)Always non-metals.

To determine which statement is correct regarding elements with valency 1, we must analyze the valency concept and the characteristics of elements.

1. Understanding Valency: Valency is the measure of the ability of an atom to combine with other atoms. An element with a valency of 1 can lose or gain one electron to form a bond.

2. Types of Elements:

   • Metals, like sodium (Na) and potassium (K), often have a valency of 1, as they readily lose one electron.
   • Non-metals, such as hydrogen (H) and fluorine (F), can also exhibit a valency of 1 by either losing or gaining an electron.

3. Classification of Elements:

   • Metals: Generally have low electronegativity and easily lose electrons.
   • Non-metals: Can either gain or share electrons to achieve a stable electron configuration.

4. Conclusion: Since elements with valency 1 may be either metals or non-metals, the correct statement is (iii) "Either metals or non-metals."

Thus, the final answer is:

Final Answer

(iii) Either metals or non-metals.