Why do the alkali metals react more violently as you go down the column in the periodic table?

Answer 1

Electron screening is the best reason for there being more reactivity as an investigator looks down the Group 1 elements, which are the Alkali metals. Let's take a step back and then come up to speed on this one. When any of the alkali metals react with water, they form a metal hydroxide, and that Group 1 element becomes the positive ion of that metal. The general reaction for any of the Alkali metals is this, where "M" is any metal: M + 2H2O --> M+ + 2OH- + H2.

For all the Group 1 elements, those Alkali metals, it is this same reaction. In going down the column, the elements' atomic numbers increase, and there are more and more electron shells in the atomic structure. The increasing number of electrons sets up a condition where the outer electrons are "screened" from the positive "pull" of the nucleus by other electrons in inner shells. These outer electrons can be "shed" or "loaned out" more easily if the nucleus isn't "hanging onto them" as tightly. Electronegativities speak to the "desire" of an element to react, and we see electronegativities decreasing as we go down the column. The further down the column you go, the more violently they react because the electronegativity of the atoms decreases down the column. Because the electronegativity is decreasing (and that is because of the increasing size of the outer electron orbitals and the screening of those outer orbitals by inner electrons), the electrons are more easily removed from the metal. That means that it is easier to form the ion, and said another way, they are more easily oxidized. That means that less energy is spent in the reaction pulling off the electron, and so the reaction is faster and more exothermic.

Answer 2

When you go down the Periodic Table, atoms get bigger in radius. The furthermost electrons' relative distance to the nucleus is then far larger. At the time an electron's distance to the nucleus is at its peak, the protons' in the original atom can attract it less than another atom's protons, thus an ionic compound is formed.

Answer 3

All atoms want to do is make their valence shell full. In alkali metals they have all of their shells completely full except one valence electron. The alkali metals REALLY want to get rid of that electron, so they will react with many elements/compounds to get rid of that electron. In alkaline earth metals they have all of their shells completely full except for two valence electrons. They also want to get rid of those electrons but the alkaline earth metals are not as desperate to do so as the alkali earth metals which make the alkaline much less reactive than the alkali metals.

Answer 4

Down in the group the electronegativity is lower and the electropositivity is greater.

Answer 5

It is easier for them to lose the atoms basically and they bacome more vulnerable so when reacted with water they lose their charged particles and react violently

Answer 6

it is as all alkali metals (group I metals) only need to give away 1 of its electron to attain full electronic configuration, thus they are very reactive.