The most reactive group in the periodic table is group one, the alkali metals.
well, there is no group 7a, but thats kind of a hard one to answer, because some groups have the same amount of reactive metals. The actinide and lanthinide series both have a large amount of reactive subsances. But those are series.
Francium
The elements in the group 17 are the most reactive non metals. In the group, the reactivity decreases downwards as the ionic radius increases. Therefore fluorine is the most reactive non metal.The halogens are the most reactive non metals. They are in the 17th group of the periodic table. Fluorine is the most reactive non metal.Chlorine is most reactive non metal.It is present in group-17. It forms bonds by gaining one electron.
Metals which can easily loose electron are most reactive. They are present in group-1.
Alkali metals. This is the most reactive group on the periodic table
Caesium and francium, in group one or in group 7 iodine or astatine.
Fluorine. One going down the Halogen Group , the elements become less reactive. Compare with the Alkali metals (Grp 1) , which become more reactive on going down the Group from Lithium to Francium.
Group 1 (alkali metals) is the most reactive group of elements. This group includes lithium, sodium, potassium, rubidium, cesium, and francium. They are highly reactive due to having only one electron in their outermost shell, which they readily donate to form stable compounds.
The halogens, group 17
Alkali Metals (group 1) because they only need to lose one electron in order to have a stable valence level of 8. As you go down the alkali metals group, the elements become more reactive. So Francium is the most reactive alkali metal. Also, Halogens, because they already have 7 electrons and only need to gain one in order to have a stable valence level of 8. As you go up the halogens group, the elements become more reactive. So Fluorine is the most reactive halogen. This is just a brief summary, if you want to know the reasons why this is I suggest you search about ionization energy, electron affinity, and electronegativity because these are all what make an element "reactive."
AnswerAlkali metals are the most reactive metalsFrancium is the most reactive metal. This is as it has many layers, the last layer having only one electron, far away from the positive pull of the proton.