Question

lithium atomic no. is 3 then protons and elecrons are 3 but neutrons is 4. why??
​

Answer 1

Answer:

lithium atom contains 3 protons in its nucleus irrespective of the number of neutrons or electrons. ... Notice that because the lithium atom always has 3 protons, the atomic number for lithium is always 3. The mass number, however, is 6 in the isotope with 3 neutrons, and 7 in the isotope with 4 neutrons.