The term univalent or monovalent describes atoms with one valence electron, i.e. a valency of 1. In simpler terms, this corresponds to an atom with one electron in its outermost orbital. All elements in the first group (group IA) are an example of this, for example hydrogen and sodium. Properties For alternative meanings see atom (disambiguation). ... In chemistry, valence electrons (vay-luhhn-cee) are the electrons contained in the valence shell of an atom, and which are likely to participate in a chemical reaction through bonding with other atoms, molecules, or ions. ... In chemistry, valency is the power of an atom of an element to combine with other atoms measured by the number of electrons which an atom will give, take, or share to form a chemical bond. ... The term orbital has several meanings: In physics and chemistry it is used to describe an atomic electron configuration, see also molecular orbital and atomic orbital. ... Generally, an element is a basic part that is the foundation of something. ... The term group can refer to several concepts: Look up Group in Wiktionary, the free dictionary In music, a group is another term for band or other musical ensemble. ... General Name, Symbol, Number Hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1 (IA), 1, s Density, Hardness 0. ... General Name, Symbol, Number sodium, Na, 11 Series alkali metal Group, Period, Block 1 (IA), 3, s Density, Hardness 968 kg/m3, 0. ...