Question

of the elements
i am in group 1 and period 2. i am the lightest metal on the periodic table. i am commonly used in rechargeable batteries and react violently with water. what element am i?
○ he
○ be
○ li
○ h

Explanation:

1. Eliminate non-Group 1 elements: He (Group 18), Be (Group 2) are not in Group 1.
2. Eliminate non-Period 2 element: H is in Period 1.
3. Verify properties: Li (Group 1, Period 2) is the lightest metal, used in rechargeable batteries, and reacts violently with water, matching all clues.

Answer:

Li