Metals are elements that readily lose one electron in their outer shell to form cations.Metals, based on their chemical properties, are grouped into three main groups in the periodic table: alkali metals, alkaline earth metals, and transition metals.Alkali metals are found on the leftmost side of the periodic table. They are elements of the S block. Since the elements of this group form alkalis when they react with water; they are called alkali metals. Alkali metals display a set of homologous behaviors. Alkali metals are a part of our day-to-day lives and are present in various things. They are mainly used in the preparation of table salt and lithium batteries. The alkali metal elements are also known as the lithium family. When compared to other metals in the periodic table, the chemical properties of alkali metals are well understood as they all have a valence electron in their outer shell. This has made it easier to study them and their chemical properties.How are alkali metals formed?Alkali metals were formed by the big bang nucleosynthesis and stars. When the Big Bang occurred, only small quantities of lithium, beryllium, and boron were formed. This was due to the absence of a stable nucleus.The formation of the earth involves the same cloud matter that was involved in the formation of the sun. During the evolution of the solar system, the Earth and other planets acquired different concentrations of chemical elements. The alkali metals do not occur in their natural state. They are found near the earth’s surface. When compared to other metals, sodium and potassium are some of the most common elements on the earth’s surface. They were formed as a result of solid deposits from the evaporation of the seas. This process can be seen in the Great Salt Lake (Utah) and the Dead Sea. Though lithium is similar to both these elements, it is not found with them. It is relatively smaller and less reactive. So, it is formed in seawater. Francium 223 is formed due to the alpha decay of actinium 227. They can also be synthesized using chemical reactions.Electrolysis of a mixture of lithium chloride and potassium chloride will form lithium metal. Sodium can be formed when caustic soda is electrolyzed. When sodium reduces molten potassium chloride at 870 C (1,600 F), potassium is created. When alkali metal carbonates are isolated, trace amounts of rubidium can be extracted from them. Fractional distillation is used to separate an alloy of cesium and rubidium. Generally, cesium is available as cesium azide (CsN3) as cesium metal is highly reactive. Francium is obtained when thorium is bombarded with protons. It can also be formed when radium is bombarded with neutrons.What do alkali metals look like?All alkali metals are similar to each other and share most of their physical properties. An alkali metal is soft when compared to other metals.Alkali metals are shiny. They are shiny due to the presence of free electrons. These free electrons cause a vibration when they meet light and generate light on their own as they vibrate. This light, when reflected back, gives alkali metals a shiny surface. Alkali metals shine the brightest when freshly cut. They lose their shine over time, as they are highly reactive.Alkali metals react vigorously with air and water and tarnish. This happens as the free electrons have restricted vibrations when they react with oxygen and carbon dioxide. All the alkali metals except cesium are silvery white. All wavelengths of incoming light may be absorbed by a metal’s surface. Due to this, the excited electrons leap to a greater vacant level of energy. When this happens, a photon of the corresponding wavelength is released due to the electricity generated. As a result, a majority of the incoming light is promptly emitted back to the surface, giving them silvery-white color.What are the different types of alkali metals?There are six different types of alkali metals. They are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).Lithium: Lithium is a silvery-white alkali metal with the atomic number 3. The element was located in a mineral, whereas all other common alkali metals were located in plant material. Similar to all other alkali metals, lithium is also volatile and combustible. During the big bang theory, lithium was one of the three elements that were produced in large quantities. Lithium does not occur in its natural form. It is found only in mixtures like pegmatitic rocks. Of all the metals, lithium is the least dense. When compared to other members of the group, lithium salts are less soluble. Lithium exhibits anomalous behaviors due to its high hydration energy.Sodium: Sodium is also a silvery-white metal with the atomic number 11. Sodium metal is soft and can even be cut using a butter knife. Sodium is an important element for all animals, humans, and some plants. It is the ninth most copious element in the human body and the sixth most prevalent element. Since it does not occur naturally, it must be synthesized. Sodium may be found in a variety of minerals, including feldspars and rock salt. In its liquid condition, sodium is also utilized as a heat transfer medium. Sodium chloride, or common salt, is its most common compound. Sodium is widely used to reduce organic compounds. Sodium is used in the production of several commercial products, such as sodium carbonate (Na 2 CO 3), caustic soda (NaOH), and baking soda (NaHCO 3 ).Potassium: Potassium, with the atomic number 19, is a malleable metal. It gets its name from potash, which is related to the plant ashes from which potassium is extracted. After lithium, potassium is the metal with the lowest density. It is a shiny white metal that quickly becomes gray when it interacts with the air. Potassium and sodium are chemically extremely similar. In supernovae, potassium is created by nucleosynthesis. Potassium is one of the most important elements. Potassium compounds have countless applications. Potassium ions are found in cells and are necessary for fluid and electrolyte regulation.Rubidium: Rubidium has the atomic number 37. Its physical properties are very similar to those of other alkali metals, such as potassium, and cesium. Leucite, carnallite, zinnwaldite, and pollucite are minerals that include rubidium. The metal’s name is derived from the Latin word ‘rubidus’, meaning ‘deep red’. The word refers to the emission color of the metal. It is the second densest alkali metal. It is easily combustible when it reacts with air. The melting point of rubidium is slightly above our body temperature. Rubidium has limited applications.Cesium: Cesium is a soft, silvery-golden alkali metal with blue spectral lines. The atomic number of cesium is 55. It is one of the five metals with a melting point close to room temperature. It is the element with the lowest electronegative potential. The minerals pollucite and lepidolite contain cesium. Cesium is an extremely rare metal that is more expensive than gold.Francium: Francium, atomic number 87, is a highly radioactive element. It is the second rarest element that occurs in its natural state. Due to its volatility and scarcity, francium has no economic use. It only has a half-life of 22 minutes. It was the final element found naturally. It has a strong resemblance to cesium. There are 34 isotopes of francium.Characteristics Of Alkali MetalsMost alkali metals are quite similar. Alkali metal elements share several physical and chemical properties.Alkali metals come under the category of soft metals. They are readily cuttable. The solidity of these metals reduces as we move down the group. Since an alkali metal has weak metallic bonding, it has a low melting and boiling points. Alkali metals react quickly when they come in contact with air and water. The one-electron that is present in the outer shell, known as the valence electron, is the reason for its highly reactive nature.In order to prevent this, they are always stored in solutions like kerosene oil. Alkali metals quickly form cations by losing their outermost electron or valence electron. Alkali metals react with atmospheric oxygen in just a few minutes. Hence, they lose their color and tarnish quickly.Alkali metals have low ionization energies. Pure alkali metals give out hydrogen gas and form basic hydroxides like sodium hydroxide when they come in contact with water. Hydrogen ions will be reduced to gaseous hydrogen. Pure metals form oxides when they come into contact with oxygen. The first ionization energy of all alkali metals is less. However, the second ionization energy is greater. (The amount of energy necessary to remove the outermost electron, or valence electron, is known as ionization energy.).During flame tests, each alkali metal generates a different color. Sodium becomes orange or yellow, lithium changes to red, potassium turns lilac, rubidium goes red, and cesium turns purple or blue. When they are dissolved in liquid ammonia, alkali metals produce blue solutions. When compared to the atomic radii of alkali metals, their ionic radii are smaller. Alkali metals produce flammable hydrogen gas when they are involved in redox reactions with certain non-metals. When they are mixed with oxoacids, they form salts. All alkali metals are electrically conductive.Did You Know?The biological life on earth is highly dependent on sodium and potassium. Over 90% of life on earth will not be able to survive without these elements as they are major sources of nutrients.The human body, on a daily basis, requires 17.6 oz (500 g ) and 0.10 oz (2.8 g) of sodium and potassium, respectively. If you are unable to meet the sodium and potassium requirements, it can cause a variety of problems and put the body in shock. A person can also go into a coma and eventually die if he or she has low levels of sodium in their body.The atomic numbers of all alkali metals are odd numbers.Heavier alkali metals and the element ammonium share a lot of similarities.You will notice the increasing atomic radius and ionic radius of alkali metals as you move down the periodic table.Atomic clocks help to maintain accuracy by using the resonance frequencies of atoms. Such clocks are made from pure elements like cesium and rubidium. Cesium atomic clocks are said to give the most accurate timings.Since cesium has a melting point that is only slightly over our body temperature, it can begin to melt if you have it in your palm.Hydrogen is not an alkali metal but is still included in group one. Then why is it placed along with alkali metals? It is because they have some common properties. Hydrogen is a strong reducing agent and has an outer electronic configuration that is similar to that of other alkali metals.Scientists are currently trying to synthesize a new alkali metal which will be called ununennium (Uue). The next alkali metal following ununennium is said to be unhexpentium (Uhp). However, results regarding the synthesis of unhexpentium have been unsuccessful due to its high atomic number.Due to the size and ionic nature, cesium ion is the least water-soluble alkali ion.Lithium carbonate is the only alkali carbonate that is not thermally stable. Lithium is the strongest reducing agent. Lithium hydride is used to produce another strong reductant, lithium aluminum chloride.A caesium metal when immersed in water will explode, while a sodium metal will burn.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for characteristics of alkali metals then why not take a look at why do metals conduct electricity, or why do metals have high melting points.
Metals are elements that readily lose one electron in their outer shell to form cations.
