What is Period 2 element?
A '''period 2 element''' is an [[Chemical element|element]] in the second [[period (periodic table)|period]] (row) of the [[periodic table]]. Period 2 has eight elements: [[lithium]], [[beryllium]], [[boron]], [[carbon]], [[nitrogen]], [[oxygen]], [[fluorine]] and [[neon]]. Their [[atomic number]]s go from 3 to 10. Period 2 elements have [[electrons]] in the first two [[electron shell]]s. The first electron shell is always full. The second electron shell ([[valence electrons]]) fills when atomic number gets bigger. Two electrons join the 2s [[atomic orbital|orbital]], and six electrons join the 2p orbitals. These atoms can become stable in two ways: * They can lose electrons so the second electron shell is empty. Lithium, beryllium, and sometimes boron do this. * They can gain electrons so the second electron shell is full, with [[octet rule|8 electrons]]. Fluorine, oxygen, nitrogen, and carbon usually do this. {{Periodic tables footer}} {{chem-stub}} [[Category:Periodic table]]