The Activity of Metals Classifying Metals Based on Activity
Predicting the Product of Key Group Metal Reactions

The Activity ofMetals

The main distinction between metals is the ease via whichthey undergo slrfc.orgical reactions. The facets towards the bottomleft corner of the regular table are the steels that are thea lot of active in the sense of being the most reactive.Lithium, sodium, and potassium all react with water, for instance.The rate of this reaction increases as we go dvery own this column,but, bereason these facets become even more active as they becomemore metallic.

You are watching: Which element is the most active metal

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Classifying MetalsBased on Activity

The steels are often split into 4 classes on the basis oftheir task, as displayed in the table below.

Typical Metals Divided into Classes on theBasis of Their Activity


Class I Metals: The Active Metals
Li, Na, K, Rb, Cs (Group IA)
Ca, Sr, Ba (Group IIA)
Class II Metals: The Less Active Metals
Mg, Al, Zn, Mn
Class III Metals: The Structural Metals
Cr, Fe, Sn, Pb, Cu
Class IV Metals: The Coinage Metals
Ag, Au, Pt, Hg

The the majority of energetic metals are so reenergetic that they readilycombine with the O2 and H2O vapor in theatmosphere and also are therefore stored under an inert liquid, suchas mineral oil. These metals are uncovered exclusively in Groups IAand also IIA of the periodic table.

Metals in the second course are slightly much less active. Theydo not react with water at room temperature, yet they reactswiftly through acids.

The 3rd class includes metals such as chromium, iron, tin,and lead, which react just through strong acids. It also containseven much less energetic steels such as copper, which only dissolves whentreated via acids that have the right to oxidize the steel.

Metals in the fourth course are so unreactive they arebasically inert at room temperature. These metals are right formaking jewelry or coins because they carry out not react through the vastmajority of the substances through which they come into dailycall. As a result, they are often dubbed the "coinagesteels."

Predicting the Productof Key Group Metal Reactions

The product of many kind of reactions in between main group metals andvarious other aspects can be predicted from the electron configurationsof the facets.

Example: Consider the reactivity in between sodium and also chlorine toform sodium chloride. It takes even more power to rerelocate an electronfrom a sodium atom to create an Na+ ion than we obtain backwhen this electron is added to a chlorine atom to form a Cl-ion. Once these ions are developed, yet, the pressure of attractionbetween these ions liberates enough power to make the followingreaction exothermic.


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Ho = -411.3 kJ/mol

The net effect of this reaction is to carry one electronfrom a neutral sodium atom to a neutral chlorine atom to create Na+and Cl- ions that have actually filled-shell configurations.

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Potassium and hydrogen have the following electronconfigurations.


K: 4s1 H: 1s1

When these elements react, an electron hregarding be transferredfrom one element to the other. We deserve to decide which element shouldshed an electron by comparing the first ionization energy forpotassium (418.8 kJ/mol) via that for hydrogen (1312.0 kJ/mol).

Potassium is a lot even more likely to lose anelectron in this reaction, which suggests that hydrogen gains anelectron to form K+ and also H- ions.

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Practice Problem 1:

Write a well balanced equation for the following reactivity.

Li(s) + O2(s) " width="17" height="9" sgi_fullpath="/disk2/slrfc.orgistry/genslrfc.org/public_html/topicreview/bp/ch9/graphics/rarrow.gif">