What are P-Block Elements?

Elements which are present on the right side of the periodic table are called p-block elements. In addition to the noble gases, they include the families of boron, mercury, nitrogen, oxygen and fluorine. These elements have diverse real-life implementations that we regularly experience around us. 

Periodic Table

A periodic table is a table showing the structured positioning of different elements. The periodic table provides the name, atomic number, atomic weight and symbols of the known elements.  It is used to solve chemistry problems and divided into rows and columns. Rows are known as periods while columns are known as groups. The p-block elements are found on the right side of the periodic table.

Example of p-elements used in daily life:  Aluminum is a significant element of the p-block used in aircraft manufacturing. Chlorine is used in the swimming pools to sanitize water, which is also a p-block element.

P-Block Elements in the Periodic Table

P-block elements are where two of the three p-orbitals of their respective shells are reached by the last electron. A p-subshell has three degenerate p-orbitals, each of which can contain two electrons.

A wide variety of elements forms the p-block of the periodic table. P-block elements contain metals, non-metals and metalloids.

Metals include aluminium, gallium, indium, thallium, tin, lead and bismuth.

Non-Metals include helium, carbon, nitrogen, oxygen, fluorine, neon and phosphorus.

Metalloids include boron, silicon, germanium, arsenic, antimony, tellurium, tolonium and astatine.

Group 13 is known as icosagens or triels.

Group 14 is known as crystollegens or teragens.

Group 15 is known as pnoctogens.

Group 16 is of metals and is known as chalcogens.

Group 17 elements are non-metals and are known as halogens.

Group 18 elements are known as noble gases.

Properties of P-Block Elements

The physical properties (such as atomic and ionic radii, ionization enthalpy, etc.), as well as chemical properties, are substantially influenced by the variation in the inner core of elements. Therefore, a great deal of variance in the properties of elements in the p-block group is found.

The conductor of heat and electricity

P-block elements are glossy and usually a good conductor of electricity and heat since they tend to lose an electron. A metal that can melt into the palm is gallium, a p-block element. Silicon is one of the most valuable metalloids in the p-block group since it is an important glass component.

Electronic configuration

Since the internal core of the electronic structure can vary, the electronic configuration of p-block elements for the complete valence shell is ns²np^1-6 (He is an exception). Each group of the p-block element is known by its first element.

Example:

• Group 13 – ns² np¹ (Boron family) 
• Group 14 - ns² np² (Carbon family)
• Group 15 - ns² np³ (Nitrogen family) 
• Group 16 - ns² np⁴ (Oxygen family) 
• Group 17 - ns² np⁵ (Halogen family) 
• Group 18 - ns² np⁶ (Noble gases) (except helium is 1s²).

Color of P-Block Elements

Group 13 – Boron is brown while others are silver-coloured.

Group 14 - Silicon and germanium are grey coloured while carbon is black.

Group 15 – All elements are different in color.

• Nitrogen is color less.
• Phosphorus is red and white.
• Arsenic is yellow.
• Antimony is grey.
• Bismuth is silvery white.

Group 16 - In this group also, all have different colours.

• Oxygen is colourless.
• Sulfur is pale yellow.
• Selenium is red.
• Tellurium is silvery-white.
• Polonium is silvery.

Group 17 – elements known as halogens and are different in colour.

• Fluorine is pale yellow.
• Chlorine is greenish-yellow.
• Bromine is reddish-brown.
• Iodine is violet-black

Group 18 -There are various colours of all the noble gases.

• Helium is red.
• Neon is green.
• Xenon is white.
• Radon is colourless.
• Krypton is purple.

Metallic Character

The p-block is the key location for storing metalloids in the periodic table. The non-metallic character declines in the group, but in the p-block, there is a steady rise in the non-metallic character from left to right. Each category continues to increase the metallic character, although it declines when we go through a span from left to right. The heaviest element in each p-block category is, in fact, the most metallic.

Atomic Density

Due to the increase in the size of the atom down the group, the atomic density of elements in the p-block increases down the group. Although it reduces as we pass over the time from left to right, this is due to the reduction in the nuclear scale of all components in the p-block over the period. Aluminium is of low density in a large number of components and is commonly used as a structural element.

Atomic Radii

When we move down the group, one additional shell is always added, so the radius of the elements always increases by going down the group. But then the atomic size reduces as we shift from left to right. This is because no extra shell is inserted from left to right during the same time, but the nuclear charge is raised, hence the size reduces.

Melting and boiling points

The points of melting and boiling steadily increase the group even though the atomic mass raises the group and therefore the intermolecular forces also increase.

Exhibit variable oxidation states

The maximum state of oxidation shown by the element of a p-block is equal to the total number of valence electrons (i.e., the sum of the s and p-electrons).

In its first row, the p-block follows the octet rule, but elements in subsequent rows show hypervalence. Generally, the reactivity of elements in a group reduces downwards.  In group 18, reactivity increases: Ne < He <Ar< Kr < Xe < Rn <Og.

The oxidation states of different elements are shown below:

• Boron family: +3
• Carbon family: -4 and +2
• Nitrogen family: -3, +3 and +5
• Oxygen family: -2, +2, +4 and +6
• Halogen family: -1, +1, +3, +5 and +7
• Noble gases: +2, +4, +6 and +8

Magnetic properties

The nature of almost all elements in the periodic table is diamagnetic except astatine, iodine, polonium and radon. The only paramagnetic element is tin.

Context and Applications

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for Bachelors and Masters in Chemistry.