Oxygen has 8 valence electrons in the product, the same as neon. Each hydrogen has 2 valence electrons, the same as helium. Nitrogen has 8 valence electrons in the product, the same as neon. Each hydrogen has 2 valence electrons, the same as helium.Д¬arbon has 8 valence electrons in the product, the same as neon. It has fewer electrons than neon and can react with electron donors. Each hydrogen has 2 valence electrons, the same as helium.Д«oron has 6 valence electrons in the product because it can only make 3 bonds. Lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen.Д«eryllium has 4 valence electrons in the product because it can only make 2 bonds. When electrons are shared between two atoms, they are included in the count of valence electrons for each. Neon doesn't have any half-filled orbitals. The half-filled hydrogen 1s orbital can combine with any other half-filled orbitals of these elements. Hydrogen can combine with all of the second role elements except neon to make molecules. Carbon has a pair of electrons in its 2s orbital (2 dots together) and 1 electron each in 2 of its 2p orbitals (2p x and 2p y, for example) represented by single dots.Д«ecause there are 4 valence orbitals, some of the elements have another electron configuration that is only slightly higher in energy. Beryllium has 2 electrons in its 2s orbital, represented by 2 dots close together. Lithium has a single electron in its 2s orbital (represented by the dot). Each of the second row elements has 4 valence orbitals: 2s, 2p x, 2p y, and 2p z. The filled shell orbital (1s 2 for these elements) can't be shared and it is not involved in any chemical bonds.

We can represent the valence electrons, those in the outermost shell, with dots. The electronic configuration of the second row (n = 2) elements is in the table. Representing the Electronic Configuration The elements in the second row, lithium through fluorine, also form bonds so that they can attain the stable, filled-shell electron configuration of neon with 8 electrons. A bond where two atoms share electrons is called a covalent bond. Two hydrogen atoms form a bond with each other to share electrons so that each has the more stable electronic configuration of helium with 2 electrons.

Helium valence electrons