Periodic Properties and their Trends

Periodic trends are particular patterns found in the periodic table that depict various aspects of a specific element, such as its size and electrical capabilities. Electronegativity, ionisation energy, electron affinity, atomic radius, melting temperature, and metallic character are all major periodic patterns. Periodic trends, which result from the periodic table’s arrangement, offer chemists with a useful tool for swiftly predicting an element’s attributes. These tendencies arise due to the elements’ identical atomic structure within their various group families or periods, as well as the periodic nature of the elements.

Electronegativity Trends

Electronegativity is a measurement of an atom’s proclivity to attract and establish bonds with electrons. Because of the electronic arrangement of atoms, this feature exists. The octet rule is followed by the majority of atoms (having the valence, or outer, shell comprising 8 electrons). Because elements on the left side of the periodic table have a valence shell that is less than half full, the energy required to obtain electrons is much more than the energy required to lose electrons. As a result, the elements on the periodic table’s left side often lose electrons when forming bonds. Elements on the right side of the periodic table, on the other hand, require less energy to gain electrons to form a complete valence shell of 8 electrons. The nature of electronegativity can be accurately defined as follows: the more disposed an atom is to gain electrons, the more probable it is to attract electrons toward itself.

The nature of electronegativity can be accurately defined as follows: the more disposed an atom is to gain electrons, the more probable it is to attract electrons toward itself.

1.Electronegativity grows from left to right across an element period. If an atom’s valence shell is less than half full, losing an electron requires less energy than gaining one. In contrast, if the valence shell is more than half full, pulling an electron into the valence shell is easier than donating one.

2.Electronegativity falls from top to bottom in a group. This is due to the fact that as the atomic number decreases in a group, the distance between the valence electrons and the nucleus rises, resulting in a larger atomic radius.

3.Noble gases, lanthanides, and actinides are notable deviations to the above laws. Noble gases have a full valence shell and often do not attract electrons. Lanthanides and actinides have more intricate chemistry that generally does not follow any trends. As a result, noble gases, lanthanides, and actinides have no electronegativity values.

4.Although transition metals have electronegativity values, there is little variation over the period and up and down a group. This is due to the fact that their metallic qualities affect their capacity to attract electrons as easily as other elements.

Trends in Metallic Characters

The metallic character of an element is defined as the ease with which an atom can lose an electron. Metallic character rises from right to left during a period because the affinity between the valence electron and the nucleus weakens, allowing for simpler electron loss. Because atomic size rises as you advance down a group, metallic character increases. The outer shells become further apart as atomic size increases. The primary quantum number rises, and the average electron density travels away from the nucleus. Because the electrons in the valence shell have less affinity to the nucleus, they can lose electrons more easily. This results in a more metallic flavour.

1. Metallic properties diminish from left to right with time.This is due to the atom’s decreased radius (produced by Zeff, as previously explained), which permits the outer electrons to ionise more easily.

2. Metallic properties improve as one moves along the group. As  electron shielding increases the atomic radius, the outside electrons ionise more rapidly than electrons in smaller atoms.

The ability to lose electrons is referred to as metallic character, while the ability to receive electrons is referred to as nonmetallic character.

Trends at Melting Point

The melting point is the amount of energy required to break a bond(s) and transition a substance’s solid phase to a liquid phase. In general, the stronger the link between an element’s atoms, the more energy is required to break that bond. A high bond dissociation energy correlates to a high temperature since temperature is directly proportional to energy. Melting points vary and do not generally follow a consistent pattern across the periodic table. Figure 7 does, however, allow us to draw some conclusions.

1. Metals have a high melting point in general.

2. The melting points of the majority of nonmetals are low.

3. Non-metal carbon has the highest melting point of any element. 4.Semimetal boron has a high melting point as well.

Trends in Atomic Radius

The atomic radius is one-half the distance between two atoms’ nucleus (just like a radius is half the diameter of a circle). This concept is complicated, however, by the fact that not all atoms are generally bonded together in the same way. Some are kept together by covalent bonds in molecules, others by ionic crystals, and yet others by metallic crystals. Nonetheless, the great majority of elements may form covalent molecules, which are made up of two similar atoms bonded together by a single covalent bond. These molecules’ covalent radii are frequently referred to as atomic radii. Picometers are used to measure this distance. Atomic radius patterns can be found all the way through the periodic table.

1. Across a period of elements, atomic size falls steadily from left to right. This is because all electrons within a period or family of elements are added to the same shell. However, protons are being added to the nucleus at the same time, making it more positively charged.

2. As the effect of growing proton number is larger than that of increasing electron number, there is a greater nuclear attraction. This means that the nucleus attracts electrons more strongly, causing the atom’s shell to be drawn closer to the nucleus. Valence electrons are pushed closer to the atom’s nucleus. As a result, the atomic radius becomes smaller.

Conclusion 

Elements are put on it in ascending atomic number order. The position of an element on the table, on the other hand, conveys a lot more about it than the number of protons in its nucleus. As we’ve seen, the periodic table offers a wealth of information about an element’s chemical and physical properties.