What is the atomic number of lithium?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 3.
The atomic number of an element is defined by the number of protons found in the nucleus of an atom of that element. Since lithium has 3 protons, its atomic number is 3. This number uniquely identifies lithium on the periodic table and determines its chemical properties.