The Key Aspects of the Group I and Group 2 Elements

The key aspects of group 1A elements with their ns¹ valence electron configurations are very active metals. They lose their valence electrons very instantly. They have low ionisation energies and react with nonmetals to make ionic solids. Alkali metals all react smartly with water to release hydrogen gas.

Included in the group 2 elements are Beryllium(Be), Magnesium(Mg), Calcium(Ca), Strontium(Sr), and Barium(Ba). Usually, there’s no need to store these elements in oil, unlike the group one elements. For a metal,The melting temperatures and densities of alkali earth metals are both low

Group 1A — The Alkali Metals

The alkali metals belong to Periodic Table Group 1A (or IA).: hydrogen (H), lithium (Li), potassium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).Except for hydrogen, these are soft, lustrous, low-melting, extremely reactive metals that tarnish when exposed to air.  The name comes from the actual fact that once these metals or their oxides are dissolved in water, a basic (alkaline) solution results. Due to their high reactivity, alkali metals are rarely (if ever) encountered in their elemental form in nature, instead appearing as ionic compounds (except for hydrogen).

In their highest-energy orbitals, alkali metals have only one valence electron (ns1).  In their respective periods, they’re the largest elements and have the lowest ionisation energies.  The electron is easily lost, forming an ion with a 1+ charge.

Except for hydrogen, the alkali metals are solids at room temperature but have low melting temperatures: lithium melts at 181ºC, sodium at 98ºC, potassium at 63ºC, rubidium at 39ºC, and cesium at 28ºC. Sodium and potassium are also relatively soft metals that can be cut with a butter knife.

The salts of group 1A elements have a high water solubility

Because the alkali metal ions are relatively large (compared to other ions from a similar period), their charge densities are low, and they are easily separated from their anions and solvated by polar solvents like water.

The alkali metals (excluding hydrogen) react violently with water, yielding metal hydroxide, hydrogen gas, and heat.

2M(s)  +  H₂O(l)  → MOH(aq)  +  H₂(g)

(Heat plus hydrogen in an oxygen atmosphere is, of course, a very dangerous combination!)  The reaction becomes a lot of vigorous together moves from high to bottom in group 1A:In water, lithium reacts aggressively, a little amount of sodium interacts even more vigorously, and even a small amount of potassium metal reacts violently, usually igniting hydrogen gas; rubidium and cesium explode.. this can be a result of the fact that the size of the component increases as we move down the group: because the size of the metal will increase, the electron is farther faraway from the nucleus, and is therefore a lot of simply removed (i.e., the ionisation energy is lower).

Group 2A — The Alkaline Earth Metals

The alkaline earth metals are found in Group 2A (or IIA) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra) (Ra). They are tougher and less reactive than group 1A alkali metals. The term originates from the fact that when these metals’ oxides were dissolved in water, they generated basic solutions and remained solids at the temperatures attainable to alchemists in ancient times. The alkaline earth metals, like the group 1A elements, are too reactive in their elemental state to be found in nature.

In their highest-energy orbitals, alkaline earth metals have two valence electrons (ns²). They have higher ionisation energies than alkali metals of the same era because they are smaller. The alkaline earth metals are usually ionised to generate a 2+ charge

The alkaline earth metals have much higher melting points than the alkali metals: beryllium melts at 1287ºC, magnesium at 649ºC, calcium at 839ºC, strontium at 768ºC, barium at 727ºC, and radium at 700ºC. They are harder metals than the group 1A elements, but are soft and light-weight compared to several of the transition metals.

Because of the greater charge densities on the 2⁺ cations, group 2A metal salts are less soluble in water than group 1A metal salts; yet, many group 2A salts are at least moderately soluble.Some group 2A salts bond powerfully to water molecules, and crystallise as hydrates; among these are Epsom salt, MgSO4·7H2O, and gypsum, CaSO4·2H2O.

Hydrogen (H, Z=1)

Although hydrogen is placed at the top of group 1A in most versions of the periodic table, it is very completely different from the other members of the alkali metal group. 

At ambient temperature, hydrogen is a colourless, odourless, and extremely combustible gas made up of diatomic molecules of H2.

The boiling point of molecular hydrogen is -253°C (20 K), whereas the freezing point is -259°C (14 K). under tremendous pressure (about two million atmospheres), it is regenerate to a metallic kind, capable of conducting electricity.  (It has been theorised that the centre of the planet Jupiter consists of metallic hydrogen.) Within the earth’s crust, it is found at a concentration of 1500 ppm (mostly in the form water and of organic compounds), creating it the 10th most abundant element.

Francium (FR, Z=87)

Francium is a very rare, radioactive  metal.  It is known as France, the country in which it was first isolated. It is found in the Earth’s crust only in trace amounts, and is one of the smallest abundant elements on the earth.  Traces of it are found in uranium ores, where it is produced in the decay series of uranium-235; there is probably only twenty to thirty grams of naturally-occurring francium in the entire Earth.

All of the isotopes of francium are radioactive , and most have half-lives of less than five minutes; the longest-lived isotope (francium-223) includes a half-life of 21.8 minutes.

Mendeleev predicted the existence of francium based on a gap in his periodic table, but it wasn’t discovered until 1939 by Marguerite Perey, Marie Curie’s assistant at the radium Institute in Paris.

Conclusion

The group one and group 2 parts of the periodic table are mentioned as the s-block elements. Further, group one elements are referred to as alkali metals, and the group 2 elements are called alkaline-earth metal .They are named so due to the alkaline  nature of the oxides and hydroxides.The alkaline earth metals have two s-electrons in their valence shells, while the alkali metals have one s-electron in their valence shells. each these metals form a mono positive ion and dipositive ions and are extremely reactive.