Chemical Properties

A chemical property is any feature of a material that emerges during or after a chemical reaction. It is any quality generated only by altering a substance’s chemical identity. Chemical properties cannot be established simply by looking at or touching a thing; the substance’s interior structure must be significantly altered to explore its chemical properties. The properties of a substance alter dramatically when it undergoes a chemical reaction, resulting in chemical transformation. Chemical properties are distinguished from physical properties, which can be determined without altering the structure of a substance.

Chemical Properties of Metals

Metals have a high density and are malleable and ductile. They combine with other metals or nonmetals to form alloys. Some metals, such as iron, rust when exposed to air. Except for lead, most metals are excellent heat and electrical conductors. All others, with the exception of mercury, are solid at normal temperatures. 

By burning the oxygen in the air, more metals produce metal oxide. When highly reactive metals are burned in oxygen, they react violently. Potassium and sodium are preserved in oil because they react with air in a matter of seconds. They fall in the category of highly reactive metals. Silver, gold, platinum, and other metals with a lower reactivity do not tarnish easily, maintaining their bright and gleaming appearance. On reacting with water, metals produce hydrogen gas and metal oxide. 

A metal hydroxide is formed when soluble metal oxides dissolve in water. Water does not react with all metals. Highly reactive metals like sodium and potassium, on the other hand, react aggressively with water, resulting in an exothermic process in which hydrogen spontaneously ignites. When a metal combines with an acid, it produces hydrogen and salt. In a metal salt solution, a more reactive metal usually displaces a less reactive metal.

Chemical Properties of Alkali Metals

Alkali metals have a silvery appearance, are soft, and are not particularly dense. They can be cut easily with a butter knife, and caesium can even melt in your hands. They have low melting points and are extremely reactive, so they must be stored in particular solutions or containers to avoid an unexpected reaction. The fact that alkali metals contain one electron in their outermost electron layer contributes to their reactivity. Like so many other metals, Alkali metals yearn for electronic structures similar to those of their notoriously stable and unreactive cousins, the noble gases.

An alkali metal’s outermost electron can be removed with extremely little energy. As a result, alkali metals lose their outermost electrons quickly and become a +1 ion. This happens so frequently that finding an alkali metal sample with all its electrons is unusual; most alkali metals exist in their ionic +1 state.

The initial ionisation energy is the amount of energy required to remove an electron from an element. The early ionisation energy of the alkali metals is the lowest of all elements. In fact, the first ionisation energy goes lower as you move down the 1A column, making caesium the most easily ionised element on the periodic table.

Reactions of Alkali Metals 

Water, halogens, and acids all react aggressively with alkali metals. Surprising amounts of heat and light are released as a result of the reactions. The letter M denotes alkali metals in chemical equations. The following are examples of reaction equations:

• Alkali metals react with oxygen to generate oxides, which are less reactive and have a duller appearance. Oxides have a lower reactivity than pure metals.
• Oxides produce hydroxide when they come into contact with water. These elements’ hydroxides dissociate entirely in water, forming powerful bases known. Sodium hydroxide (NaOH), also known as lye, is a strong industrial base.
• Water can also react immediately with a pure alkali metal. The metal in this situation is a basic anhydride. Gaseous hydrogen is emitted, which is flammable. 
• When an alkali metal is exposed to a halogen, a very exothermic reaction occurs, resulting in an ionic salt. Almost all alkali metal salts are very soluble in water. They form conducting solutions, demonstrating that they are ionic.

Conclusion

The majority of alkali metals have a wide range of uses. Rubidium and caesium atomic clocks are two of the most well-known applications of the pure elements, with caesium atomic clocks being the most precise representation of time known as of 2012. The sodium-vapour lamp, which provides very efficient light, is a popular application of sodium compounds. Table salt, also known as sodium chloride, has been used since antiquity. Chemical properties can be utilised to create categories of chemicals. They can also be used to detect unknown chemicals and separate or purify them from others. In most cases, the chemical properties of a substance will be used to influence its uses in materials science.