To determine the group of the periodic table where an element that forms a 1-ion is typically found, let's approach this step-by-step.
1. Understanding Ion Formation:
- Atoms form ions by either losing or gaining electrons to achieve a stable electron configuration, often resembling the nearest noble gas.
- Elements that form a +1 ion lose one electron, while elements that form a -1 ion gain one electron.
2. Group Characteristics:
- Group 1 (Alkali Metals): Elements in Group 1, such as lithium (Li), sodium (Na), and potassium (K), have one electron in their outermost shell. They tend to lose this single electron easily to achieve stability, forming a +1 ion.
- Group 17 (Halogens): Elements in Group 17, such as fluorine (F) and chlorine (Cl), have seven electrons in their outermost shell. They tend to gain one electron to achieve a stable configuration, forming a -1 ion.
3. Given the Nature of the Ion:
- The question specifies an element forming a 1-ion, which implies it forms a positive ion (cation) by losing one electron.
4. Conclusion:
- An element that forms a +1 ion is typically found in Group 1 of the periodic table.
Therefore, the answer is:
- B. 1
