| Group 1 of the periodic table of elements, generally | | | | as an alkali metal. First and most obviously, it is not a |
| consists of the unique orphan element, hydrogen | | | | metal; additionally, it bonds according to what is called |
| below which is the cluster of six alkali metals: lithium, | | | | the duet rule, such that it shares two electrons with |
| sodium, potassium, rubidium, cesium, and francium. | | | | another element. Further, as it is short of one |
| While the last three elements are extremely rare, and | | | | electron to attain the stable configuration of helium, it |
| have little to do with everyday life, it is hard to | | | | may be included with halogens too. |
| spend a day without encountering at least one of the | | | | The term "alkali" (essentially the opposite of an acid) |
| first three, particularly sodium, found invariably in table | | | | refers to a substance that forms the negatively |
| salt. Moreover, along with potassium, sodium is an | | | | charged hydroxide ion (OH?) in contact with water. |
| important component of the human diet, and in | | | | On their own, however, alkali metals almost always |
| compounds with other species, it has an almost | | | | form positive ions, or cations, with a charge of +1. |
| endless array of uses. Though lithium does not have | | | | When alkali metals react with water, one hydrogen |
| as many applications, but to many people who have | | | | atom splits off from the water molecule to form |
| received it as a medication for bipolar disorder, it is | | | | hydrogen gas, while the other hydrogen atom joins |
| quite literally a life-saver. | | | | the oxygen to form hydroxide. Where the heavier |
| Though there are lengthy discussions concerning the | | | | members of the alkali metal family are concerned, |
| relationship between electron configuration and the | | | | reactions can often be so vigorous that the result is |
| definition of a particular collection of elements as a | | | | combustion or even explosion. Alkali metals also react |
| "family" in standard general chemistry books, it | | | | with oxygen to produce. Shiny and soft enough to |
| seems desirable to touch upon the subject only | | | | be cut with a knife, the alkali metals are usually white |
| lightly, inasmuch as it relates to the alkali metals. All | | | | (though cesium is more of a yellowish white). When |
| members of Group 1 on the periodic table of | | | | placed in a flame, most of these substances produce |
| elements have a valence electron configuration of | | | | characteristic colors: lithium, for instance, glows bright |
| ns1. This means that a single electron is involved in | | | | red, and sodium an intense yellow. Heated potassium |
| chemical bonding, and that this single electron moves | | | | produces a violet color, rubidium a dark red, and |
| through an orbital, or range of probabilities, roughly | | | | cesium a light blue. This makes it possible to identify |
| corresponding to a sphere. Most elements bond | | | | the metals, when heated, by color—a useful trait, |
| according to what is known as the octet rule, | | | | since they are so often inclined to be bonded with |
| meaning that when two or more atoms are bonded, | | | | other elements. |
| each has (or shares) eight valence electrons. It is for | | | | As we move across the rows or periods of the |
| this reason that the noble gases, at the opposite side | | | | periodic table, we note that the mass of atoms |
| of the periodic table from the alkali metals, almost | | | | increases, as does the energy each atom possesses. |
| never bond with other elements: they already have | | | | Yet the amount of energy required to turn a solid |
| eight valence electrons. The alkali metals, on the | | | | alkali metal into a liquid, or to vaporize a liquid alkali |
| other hand, are quite likely to find "willing partners," | | | | metal, actually decreases with higher atomic number. |
| since they each have just one valence electron. This | | | | In other words, the higher the atomic number, the |
| brings up one of the reasons why hydrogen, though | | | | lower the boiling and melting points. |
| it is also considered as part of Group 1, is not included | | | | |