Because between these two families of chemical elements a big difference of electronegativities exist.

When alkali metals become ions they loose a single electron from their outer shell and become electrostatically attracted to the ion they lost it too as the other ion should have an opposite charge, though not always equal. Like if you bonded sodium with a group 5 element you would need 3 alkali ions and a single group 5 ion. Brilliant.

Also worth mentioning, because alkali metals (group one) only have to loose one electron to gain a full outershell, they do so readily, making them very reactive.

Alkali metals are found in group 1 of the periodic table. They will form ions with a 1+ charge. If you meant alkaline earth, they are found in group 2, and will form ions with a 2+ charge.

Francium

Crack a book and look at a periodic table. The group is the number at the top of the verticle columns. Alkali metals are group 1A.

an explsion LOL, no, iv been searchin for the answer myself for a few days now At last i found it and its very simple: Hydrogen gas is produced. Hope it helped

Caesium. Francium may be more reactive but it is radioactive as well as chemically very reactive and so there are many uncertainties regarding its properties.

Iodine is not a metal.

Because all alkali meals have same no of electrons (only one) in their outermost shell

They down in a verticle column. this is representing a family or group of chemicals lol

What causes these to be so reactive is the amount of electrons in the outer most level. Each level after the first (which has 2 if full) if filled will have 8 electrons. Halogens have less than that causing it to be reactive to other elements. (i don't know how many electrons it has in the outer level) The reason why it is reactive is (depending on how many electrons it has in the outer leve) because it is either trying to gain or lose those extra electrons. What causes these to be so reactive is the amount of electrons in the outer most level. Each level after the first (which has 2 if full) if filled will have 8 electrons. Halogens have less than that causing it to be reactive to other elements. (i don't know how many electrons it has in the outer level) The reason why it is reactive is (depending on how many electrons it has in the outer leve) because it is either trying to gain or lose those extra electrons.

Groups 3-12 do not have individual names. Instead, all of these groups are called transition metals. The atoms of transition metals do not give away their electrons as easily as atoms of the Group 1 and Group 2 metals do. So, transition metals are less reactive than alkali metals and alkaline-earth metals are.

I.E is the energy required to remove one electron from each atom to form gaseous charged cations.from group 2 to 12,atomic radius increases and hence there is less attraction from the protons in the atom.therefore,the energy required to remove an electron from the outermost shell will be less

Every alkali metal has only one electron in the outermost energy level. They give it away to form monopositive ions which have stable electron configurations ending with ns2 np6 (where n is a counting number between 2 and 7 inclusive).

Potassium

No, cesium is an alkali metal. Metals do not react with one another.

Cesium reacts with nonmetals and acids to form salts.

Because they decompose the water to pure hydrogen and oxygen. The hydrogen is a flammable gas and the oxygen is the oxidizing agent that reacts together in an explosive manner.
Caesium

Alkali metals are powerful reducing agents, they give up one electron easily. They are extremely reactive.

An alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Alkalis are best known for being bases (compounds with pH greater than 7) that dissolve in water. chemical compound is a substance consisting of two or more elements chemically bonded together in a fixed proportion by mass

Metals as found in the Periodic Table have no "extra" electrons. They are electrically neutral because they have the same amounts of protons and electrons or + and - charges respectively.

However metals react with non-metals to form Ions, cations to be more precise, in this case they actually lose electrons resulting in a positive charge. In other words, metals never have "extra" electrons, they either have a neutral charge or they are lacking electrons and have a negative charge.

Alkaline metals are extremely reactive to H20. Since there is moisture in our skin, we should avoid handling it without gloves. This why the more reactive ones are stored in oil, to avoid them reacting to the moisture in the air.

Li

Lithium

Sodium, Potassium, Rubidium, Caesium, and Francium