p-Block Elements – Definition, Properties, Uses, Examples

Some metals, all nonmetals, and metalloids are among these elements. Normal or representative elements are s-block and p-block elements combined (except zero group elements). Each periodic table period concludes with a member of the zero group (18th group), i.e. a noble gas with a closed shell ns²np⁶ configuration. Prior to the noble gas group, there are two chemically significant non-metal groups. These are halogens (group 17) and chalcogens (group 18).

p-Block Elements

p-block elements are those in which the last electron occupies p-orbitals and are found in groups 13, 14, 15, 16, and 17 (except helium). Because p-block orbitals can only hold a maximum of six electrons, p-block elements are classified into six groups.

The first element of each group of p-block elements identifies it. Group 13 is known as the Boron Family, Group 14 as the Carbon Family, Group 15 as the Nitrogen Family, Group 16 as the Oxygen Family, Group 17 as the Halogen or Fluorine Family, and Group 18 as the Noble Gas Family or Neon Family. Helium is not a p-block element, but it is in the noble gas family because it is also a noble gas. Helium is one of the s-block elements.

Properties of p-Block Elements 

• The last electron in the atoms of the p-block elements enters the p-subshell of the outermost shell.
• The np subshell is gradually filled up in these elements. The configuration of the valence shell ranges from ns² np¹ to ns² np⁶.
• The general electronic configuration of p-block elements is ns²np^1-6 (Except Helium).
• The number of electrons in the p-block element’s penultimate shell is either 2 or 8 or 18.
• Except for f and inert gases, p-block elements have a range of oxidation states ranging from +n to (n- 8), where n is the number of electrons in the outermost shell.
• The p-block elements have covalency in general, but higher members can have electrovalency. Highly electronegative elements, such as halogens F, Cl, and others, exhibit electrovalency by accepting electrons and forming anions. Some of the elements also have coordinate valency.
• There is a consistent increase in non-metallic character from left to right. Non-metallic character, on the other hand, decreases from top to bottom in the groups.
• Ionization energies increase from left to right in a period and decrease from top to bottom in a group. Because of the half-filled and fully filled orbitals in the valency shell, members of groups VA and zero have extremely high ionization energies.
• Reducing nature decreases from left to right in every period, while oxidizing nature increases. Nature is reduced from top to bottom in a group. Halogens are powerful oxidizers.
• The majority of the p-block elements react to form acidic oxides.
• No member of the p-block series or salts imparts a distinct colour to the flame.
• A number of p-block series elements exhibit the phenomenon of allotropy. Carbon, silicon, phosphorus, sulphur, boron, germanium, tin, arsenic, and other elements exhibit this property.
• Many p-block series elements, such as carbon, silicon, germanium, nitrogen, oxygen, sulphur, and others, exhibit catenation property.

Uses of p-block Elements  

1. Borax, a boron compound, is used in the glass and pottery industries.
2. Boron is also used in the detergent and soap industries.
3. Boron is used in aircraft as well as bulletproof vests.
4. Boron is used to increasing the hardness of steel.
5. Aluminium is used in utensils, coils, cables, iron and zinc protection, and foils to wrap articles. It is also used as a reducing agent.
6. As semiconductors, germanium, arsenic, silicon, and gallium are used.
7. Alum is used as a water purifier and as an antiseptic.
8. Iodine tincture contains iodine.
9. Disinfectants contain chlorine.
10. Carbon and its compounds are used in a variety of applications.

Some important compounds of p-block

Ammonia: Ammonia (NH₃) is a nitrogen and hydrogen compound that is necessary for life. It is formed as a result of the regular decay of vegetable and animal bodies. The demise and rot of animals and plants cause the nitrogen compounds found in them to deteriorate, resulting in the production of ammonia. Ammonia, in the form of ammonium salts, is present in the soil.

Ammonia is a type of gas. It is devoid of colour. It has a strong, pungent odour and a soapy taste. When it is suddenly inhaled, it attacks the eyes, causing tears. It is less dense than air. It dissolves easily in water. At room temperature and a pressure of around 8-10 atmospheres, ammonia easily melts.

Ozone: Ozone is an oxygen allotrope. It has a high level of instability in nature. Its traces can be found about 20 kilometres above sea level. It is created when oxygen reacts with the sun’s ultraviolet rays. This gas’s primary function is to shield the earth’s surface from harmful ultraviolet radiation from the sun. We use chlorofluorocarbons in refrigerators and other aerosols, which emit harmful substances into the air, causing gaps in the layer. As a result, we get UV light, which causes a lot of skin problems and cancer in people.

Ozone is a gas that has a slight bluish hue. It has a fishy odour. At –120°C, it condenses into a dull blue fluid. It hardens into dark violet crystals as it cools further. It is very unstable thermodynamically and disintegrates to oxygen. This is an exothermic process that is catalyzed by a variety of materials. However, we must be aware that high concentrations of gas can be extremely hazardous.

Sulphuric Acid: Sulphuric acid (H₂SO₄), is a colourless, odourless liquid. It is also extremely corrosive. Oil of Vitriol is another name for it. It has been referred to as the “King of Chemicals” due to its wide range of applications. Furthermore, we can find it in both combined and free form.

Sulfuric acid is a colourless, thick, oily fluid. At 298 K, it has a specific gravity of 1.84. The acid’s boiling point is 611 K. This chemical’s higher boiling point and thickness are due to hydrogen bonding. This strong chemical reacts vigorously with water, releasing a lot of heat. Thus, we must never add water to H₂SO₄.

Phosphine: Phosphine is a chemical that belongs to the class of organophosphorus compounds. In 1783, Philippe Gengembre discovered or acquired this chemical. He was the one who discovered phosphine by heating phosphorous in an aqueous potassium carbonate solution. The chemical formula for phosphonate is PH₃. The concentration of this compound in our environment changes all the time. This chemical, as previously stated, plays an important role in the phosphorus biochemical cycle.

Phosphines are odourless and colourless gases. It has a distinct odour, similar to that of spoiled fish. It is a highly noxious gas. In water, it dissolves slowly. It can, however, dissolve in natural solvents. By reacting with hydrogen iodide, it acts as a Lewis base by giving away its lone pair of electrons. It is a non-ignitable gas under normal conditions. When heated, however, it bursts into flames, releasing phosphoric acid. When we expose it to oxidising agents, it explodes violently.

Sample Questions 

Question 1: What are the 17 non-metals?

Answer:

Except for hydrogen, which is found in the upper left corner, nonmetals are located on the extreme right side of the periodic table. Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorus, Sulphur, Chlorine, Argon, Selenium, Bromine, Krypton, Iodine, Xenon, and Radon are the 17 nonmetal elements.

Question 2: What is the general electronic configuration of p,d and f-block elements?

Answer:

The general electronic external configuration for p block components is ns²np⁽¹⁻⁶⁾. (n−1)d⁽¹⁻¹⁰⁾ns⁽⁰⁻²⁾ is the general electronic outer configuration of d-block elements. The general electronic outer f-block element configuration is (n−2)f(⁰⁻¹⁴⁾(n−1)d⁽⁰⁻¹⁾ns².

Question 3: What are the properties of sulphuric acid?

Answer:

Sulfuric acid is a colourless, thick, oily fluid. At 298 K, it has a specific gravity of 1.84. The acid’s boiling point is 611 K. This chemical’s higher boiling point and thickness are due to hydrogen bonding. This strong chemical reacts vigorously with water, releasing a lot of heat.

Question 4: How is ammonia formed?

Answer:

The regular decay of vegetable and animal bodies produces ammonia. The demise and rot of animals and plants causes the nitrogen compounds found in them to deteriorate, resulting in the production of ammonia. Ammonia exists in the soil as ammonium salts.. 

Question 5: How does ozone protect us?

Answer:

Ozone shields the earth’s surface from the sun’s harmful ultraviolet rays. We use CFCs in refrigerators and other aerosols, which release harmful substances into the air, causing gaps in the layer. As a result, we get UV light, which causes a lot of skin problems and cancer in people.