You more than likely think the water together a problem that deserve to put out fires. But some elements are therefore reactive the they burn in water. In fact, they basically explode in water. An example is shownin the picture below. About 3 pounds of salt were added to water, and also the an outcome was an explosive reaction. Why is sodium such a reactive element? In this section, you will find out.

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Figure (PageIndex1): sodium reacting through water.

The first Group

Sodium (left( ceNa ight)) is an facet in team 1 of the regular table of the elements. This group (column) that the table is displayed below. It has the nonmetal hydrogen (left( ceH ight)) and six metals dubbed alkali metals. Aspects in the same group of the routine table have actually the same number of valence electrons. These room the electron in the outer power level that the atom that have the right to be affiliated in betterworld2016.orgical reactions. Valence electron determine many of the nature of an element, so facets in the same team have similar properties. Every the elements in team 1 have just one valence electron. This provides them very reactive.

Figure (PageIndex2): team 1 the the periodic table.

Reactivity of team 1 Elements

Hydrogen is a really reactive gas, and also the alkali metals are even more reactive. In fact, they room the most reactive metals and, along with the facets in team 17, are the most reactive of every elements. The reactivity of alkali metals increases from the peak to the bottom of the group, therefore lithium (left( ceLi ight)) is the least reactive alkali metal and also francium (left( ceFr ight)) is the most reactive. Due to the fact that alkali steels are so reactive, they are discovered in nature just in combination with other elements. Lock often incorporate with group 17 elements, i m sorry are really "eager" to acquire an electron.

Other properties of Alkali Metals

Besides being very reactive, alkali metals share a number of other properties:

Alkali steels are every solids in ~ room temperature. Alkali metals are low in density, and some of lock float ~ above water. Alkali steels are relatively soft. Some are even soft enough to cut with a knife, favor the sodium pictured in the figure below.

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api/deki/files/78133/CK12_Screenshot_6-9-4.png?revision=1&size=bestfit&width=406&height=238" />Figure (PageIndex4): Hydrogen has actually the smallest, lightest atoms of every elements. Pure hydrogen is a colorless, odorless, tasteless gas the is nontoxic but highly flammable. Hydrogen gas exists mostly as diatomic ("two-atom") molecules (left( ceH_2 ight)), as shown above. Hydrogen is the many abundant aspect in the universe and also the 3rd most abundant element on Earth, and occurs mainly in compound such as water.what is the least reactive metal