Which is the electron configuration for lithium?
o 15²
o 253
1822s1
O 151252

Explanation:

the atomic number of lithium is 3 thats why the electronic configuration of lithium is 1s2,2s1

these nuts

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.