Anomalous Properties of the First Element

Some S-block elements of the periodic table, such as lithium and beryllium, have distinct characteristics in comparison to other elements in the same group for a variety of reasons. Elements are organized in a periodic table in a row-by-row and column-by-column fashion based on their chemical and physical characteristics.

The elements in the first column are referred to as Group 1 elements, and they include lithium, sodium, potassium, rubidium, Caesium, and Francium. All of these elements have similar properties with the exception of lithium, hence all of the elements in this group, including lithium (which has distinct properties), are referred to as Alkali Metals.

The elements in the second column are referred to as Group 2 elements, and they include beryllium, magnesium, calcium, strontium, barium, and radium. Except for Beryllium, all of these elements have comparable characteristics, hence all of the elements in this group are known as Alkaline Earth Metals.

Comparison between physical properties of Alkali Metals and physical properties of Lithium

1. Group 1 elements are soft; however, lithium is particularly hard compared to the other elements in this group.
2. Group 1 elements tend to have a lower boiling point than alkaline earth metals, although lithium has a very high boiling point.
3. In comparison to alkali metals, Lithium has the shortest ionic radius in the group.
4. The ionization enthalpy of lithium is greater than that of alkali metals.

Chemical Properties of Lithium

1. Depending on the metal and its size, alkali metals react aggressively with oxygen, forming oxides, peroxides, and superoxides. Among alkali metals, lithium is the sole element that forms an oxide, whereas the others form peroxides and superoxides.

4Li + O₂ → 2Li₂O

2. Alkali metals react with water to produce hydroxides and emit H2 gas; however, the reaction of lithium with water is less violent than that of other alkali metals, despite the fact that the value of Standard potential for lithium is the most negative.

2X + 2H₂O → 2M++ 2OH^– + H₂ ,where X is an alkali metal.

3. Alkali metals react with the halogen group, which consists of fluorine, chlorine, bromine, and iodine, to generate related ionic halides, whereas lithium forms covalent halides.

2M + X₂ → 2MX , where X is a halogen and M is an alkali metal.

4. Alkali metals may react with hydrogen to generate equivalent hydrides at high temperatures of about 673 K, whereas lithium typically interacts with hydrogen at extremely high temperatures around 1073 K.

5. Alkali metals are reducing in nature, with lithium being the most powerful reducing agent.

Comparison between physical properties of Alkali Metals and physical properties of Beryllium

1. Alkaline earth metals have a silvery-white appearance, whereas beryllium has a steel-gray appearance.
2. Beryllium has a substantially higher boiling point than all other metals.
3. Beryllium is a harder element than the others in this group.
4. Beryllium has the shortest ionic radius in the group.
5. Beryllium has a higher ionization enthalpy than alkaline earth metals.

Chemical Properties of Beryllium

1. Hydroxides are formed when alkaline earth metals react with water. Beryllium is the only element in Group 2 that does not react with water due to the protective layer that forms on the surface of this alkaline metal.
2. Alkaline earth metals react with the halogen group, which includes fluorine, chlorine, bromine, and iodine, to generate matching ionic halides, whereas Beryllium forms covalent halides.
3. Alkaline earth metals have a tendency to react with acids to produce hydrogen gas, but Beryllium does not.
4. Alkaline earth metals also react with air to generate various metal oxides. Among the group 2 elements, Be is the only one that does not react with air, owing to the protective layer that forms on the surface of these metals.
5. Alkaline earth metals may react with hydrogen to generate equivalent hydrides when heated. Except for Be, which forms covalent hydrides, alkaline earth metal hydrides are metallic hydrides.

Anomalous Properties of Lithium

There are several significant distinctions between lithium and other alkali metals:

1. Alkali metals create hydrogen carbonates in the solid phase, but lithium’s hydrogen carbonate cannot be generated in the solid-state.
2. Lithium Chloride has the capacity to create hydrates, whereas the other alkali metals cannot.
3. All alkali metals, with the exception of lithium, have a propensity to create ethynide when interacting with ethyne.
4. Alkali metal fluorides are easily soluble in water, whereas lithium fluoride is less so.
5. When alkali metal nitrates are heated, they generate nitrites, whereas lithium nitrate produces lithium oxide.

Reasons for Lithium’s Abnormal Properties

The anomalous characteristics of lithium are caused mostly by two factors:

1. Size: The atomic size of lithium is extremely tiny.

2. Polarizing power: Polarizing power may be defined as the ratio of an element’s charge to its radius. Lithium has a strong polarizing power due to its small size hence the charge divided by radius yields a large value.

Lithium Applications:

1. Lithium-aluminum alloy is extremely robust and is utilized in the production of components for various aircraft and combat jets.
2. Lithium is used to create many alloys, one of which is known as white metal.
3. Armor plates that are both strong and light are created by combining lithium and magnesium.
4. Lithium is also utilized in electrochemical cells to store energy.
5. Lithium isotopes are employed in nuclear processes.

Anomalous Properties of Beryllium

There are several significant distinctions between beryllium and other Alkaline Earth Metals:

1. Beryllium Sulphate is easily dissolved in water, whereas other alkaline earth metal sulfates are not.
2. Beryllium oxides and hydroxides are amphoteric in nature, whereas oxides and hydroxides of other alkaline earth metals are ionic.
3. Beryllium nitrate is anhydrous, but other alkaline earth metal nitrates are not.
4. Beryllium does not easily react with acids due to the protective layer on its surface.
5. Carbonates of alkaline earth metals are stable, but beryllium carbonate is unstable; thus, it is kept in a carbon dioxide atmosphere safe.

Beryllium Applications

1. Beryllium is employed to manufacture many components of computers, weapons, and airplanes.
2. Beryllium, when combined with copper, is employed in the production of strong springs used in vehicle shock absorbers.
3. Beryllium is employed in the production of several alloys.
4. Used to make spaceship reflectors.
5. Beryllium isotopes are employed in nuclear processes.

Reasons for Beryllium’s Abnormal Properties

The anomalous characteristics of beryllium are caused mostly by two factors:

1. Size: Because beryllium’s atomic size is so tiny in comparison to other elements in the same group, it does not exhibit the same patterns as other alkaline earth metals.
2. Atomic Number: Because beryllium has an atomic number of 4, its coordination number cannot be more than 4, although other members of the same group can have a coordination number of 6.