Periodic Trends Explained
Periodic trends are specific patterns within the periodic table that illustrate different aspects of an element. They were first discovered in 1863 by Russian chemist Dmitri Mendeleev. Let’s look at some examples. These trends show the properties of elements, such as melting and boiling points. They are important in understanding the chemical and physical properties of various elements.
Ionization enthalpy is the amount of energy required to excite an atom. Its magnitude increases from left to right in the periodic table, due in part to the increasing positive charge in the nucleus. The increased positive charge means that the valence electrons, which are tightly bound to the nucleus, are more difficult to excite, so that the amount of ionization enthalpy required to liberate them is greater.
The IE of an element is determined by the electron configuration in its nucleus. This electron configuration determines both the atom’s chemical and physical characteristics. The nuclear charge and the number of electron shells in an atom also determine the ionization energy of an element. The size of the atom also affects the amount of ionization energy a substance has. Larger atoms tend to have lower ionization enthalpy than smaller ones.
Atomic radius is the distance between the nucleus and the outermost electron. This distance is an indication of the size of an atom. Though atomic radius is a fuzzy concept, it can be estimated from a variety of experimental techniques, such as x-ray crystallography.
The atomic radius can be explained by the valence electrons’ attraction to the nucleus. The outermost electron is the outermost one; hence the radius.
If you’re interested in the physics of gas atoms, you’ve probably heard of electron affinity. The term comes from the fact that a process in which electrons are captured results in an energy release. In other words, the process is exothermic. However, you must remember that electron affinity is not the same as enthalpy change. The enthalpy change of an electron capture is negative, whereas electron affinity is positive.
Electron affinity increases as a periodic trend. This means that as you progress up the periodic table, your electron affinity increases. This is because the valence shell gets fuller. Group 17 atoms, for example, would lose an electron more easily than a group 18 atom. In addition, the added electron would become unstable and ejected rapidly. However, as you move down the periodic table, your electron affinity decreases. This is because the electron affinity is determined by the electron’s energy.
Melting and boiling points
The patterns in bonding and structure of elements are responsible for determining their melting and boiling points. For example, elements with giant structures need more energy to break apart the bonds than do elements with smaller structures. Similarly, elements with weaker bonds need more energy to melt than those with stronger bonds.
Melting and boiling points are related to the amount of hydrogen bonding and the relative molecular mass of different substances. In general, polar substances have higher melting and boiling points than non-polar substances. As the molecular mass increases, the melting and boiling points of different compounds increase. Examples of compounds with higher melting and boiling points include hydrogen fluoride and ammonia.