query: has_part phenanthroline
supports: An ion is an atom or a molecule in which the total number of electrons is not equal to the total number of protons, giving the atom or molecule a net positive or negative electrical charge. Ions can be created, by either chemical or physical means, via ionization. A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge. However, in quantum physics, organic chemistry, and biochemistry, the term "molecule" is often used less strictly, also being applied to polyatomic ions. An organic compound is virtually any chemical compound that contains carbon, although a consensus definition remains elusive and likely arbitrary. Organic compounds are rare terrestrially, but of central importance because all known life is based on organic compounds. The most basic petrochemicals are considered the building blocks of organic chemistry. Phenanthroline ( phen ) is a heterocyclic organic compound . It is a white solid that is soluble in organic solvents . It is used as a ligand in coordination chemistry , it forms strong complexes with most metal ions . In terms of its coordination properties , phen is similar to 2,2 ' - bipyridine ( bipy ) . In chemistry, a coordination complex consists of a central atom or ion, which is usually metallic and is called the "coordination centre", and a surrounding array of bound molecules or ions, that are in turn known as "ligands" or complexing agents. Many metal-containing compounds, especially those of transition metals, are coordination complexes. A coordination complex whose centre is a metal atom is called a metal complex. In organic chemistry, functional groups are specific groups (moieties) of atoms or bonds within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of. However, its relative reactivity can be modified by other functional groups nearby. The atoms of functional groups are linked to each other and to the rest of the molecule by covalent bonds. Any subgroup of atoms of a compound also may be called a radical, and if a covalent bond is broken homolytically, the resulting fragment radicals are referred as free radicals. Functional groups can also be charged, e.g. in carboxylate salts (-COO), which turns the molecule into a polyatomic ion or a complex ion. A metal (from Greek  "métallon", "mine, quarry, metal") is a material (an element, compound, or alloy) that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable  that is, they can be hammered or pressed permanently out of shape without breaking or cracking  as well as fusible (able to be fused or melted) and ductile (able to be drawn out into a thin wire). About 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms. In chemistry, an electron pair or a Lewis pair consists of two electrons that occupy the same orbital but have opposite spins. The electron pair concept was introduced in a 1916 paper of Gilbert N. Lewis.
  Because electrons are fermions, the Pauli exclusion principle forbids these particles from having exactly the same quantum numbers. Therefore, the only way to occupy the same orbital, i.e. have the same orbital quantum numbers, is to differ in the spin quantum number. This limits the number of electrons in the same orbital to exactly two. Bond order is the number of chemical bonds between a pair of atoms. For example, in diatomic nitrogen NN the bond order is 3, in acetylene the bond order between the two carbon atoms is also 3, and the bond order is 1. Bond order gives an indication of the stability of a bond. An element with bond order value 0 cannot exist, but compounds can have a 0 bond value.  A chemical compound (or just compound if used in the context of chemistry) is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. There are four types of compounds, depending on how the constituent atoms are held together: molecules held together by covalent bonds, ionic compounds held together by ionic bonds, intermetallic compounds held together by metallic bonds, and certain complexes held together by coordinate covalent bonds. Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service (CAS): its CAS number. Carbon (from "coal") is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalentmaking four electrons available to form covalent chemical bonds. Three isotopes occur naturally, C and C being stable, while C is a radioactive isotope, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity. In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs. The nature of metalligand bonding can range from covalent to ionic. Furthermore, the metalligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligand."
candidates: a atom c carbon chemical compound chemistry e electron element group metal n nitrogen numbers order part spin wire
answer: carbon