Atomic radius and ionization energy
- Periodic Trends
- 9.9: Periodic Trends: Atomic Size, Ionization Energy, and Metallic Character
- What is the relationship between atomic radius and ionization energy?
Ionic Radius vs Atomic Radius Periodic Trendand does
The periodic table of elements has a total of entries. Elements are arranged in a series of rows periods in order of atomic number so that those with similar properties appear in vertical columns. Elements in the same period have the same number of electron shells; moving across a period so progressing from group to group , elements gain electrons and protons and become less metallic. This arrangement reflects the periodic recurrence of similar properties as the atomic number increases. For example, the alkali metals lie in one group Group 1 and share similar properties, such as high reactivity and the tendency to lose one electron to arrive at a noble-gas electron configuration.
Ionization energy by definition is the energy required to move an electron from a gaseous atom or ion. Atomic radius is the measure of the size of an atom. An estimate of the radius, or distance, between the nucleus and the electron on the furthest occupied shell. As for the atom structure, the positive nucleus is in the center, and the negatively charged electrons are around, so the only force relatively acting on the electron that will affect the ionization energy is the electrostatic force by the nucleus. Therefore the closer the electron to the nuclear the higher the attraction force, and thus the higher the energy required to overcome this attraction and remove the electron. Therefore the smaller the radius the higher the ionization energy, and the bigger the radius the lower the energy need. What is the relationship between atomic radius and ionization energy?
One of the reasons the periodic table is so useful is because its structure allows us to qualitatively determine how some properties of the elements vary versus their position on the periodic table. The variation of properties versus position on the periodic table is called periodic trends. There is no other tool in science that allows us to judge relative properties of a class of objects like this, which makes the periodic table a very useful tool. Many periodic trends are general. There may be a few points where an opposite trend is seen, but there is an overall trend when considered across a whole row or down a whole column of the periodic table. The first periodic trend we will consider atomic radius.
They will all increase generally with increasing atomic number. Generally, the atomic radius increases with element size atomic number. Ionization energy and electron affinity also increase with increasing atomic number, but primarily along the same row left to right of elements in the Periodic Table. Of these, atomic radius is the most predictable, and ionization energy and electron affinity trends follow at least in part from such trends. In general, the atomic radius except for many transition metals has a pattern where it decreases from the bottom-left to the top-right of the periodic table. Effective nuclear charge increases from left to right.
Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its size and its electronic properties. Major periodic trends include: electronegativity , ionization energy , electron affinity , atomic radius , melting point, and metallic character. Periodic trends, arising from the arrangement of the periodic table, provide chemists with an invaluable tool to quickly predict an element's properties. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements. Electronegativity can be understood as a chemical property describing an atom's ability to attract and bind with electrons. Because electronegativity is a qualitative property, there is no standardized method for calculating electronegativity.
9.9: Periodic Trends: Atomic Size, Ionization Energy, and Metallic Character
Ionization Energy and Atomic Radius
What is the relationship between atomic radius and ionization energy?
Ionization energy is the energy required to remove an electron from a gaseous atom or ion. The first or initial ionization energy or E i of an atom or molecule is the energy required to remove one mole of electrons from one mole of isolated gaseous atoms or ions. You may think of ionization energy as a measure of the difficulty of removing electron or the strength by which an electron is bound. The higher the ionization energy, the more difficult it is to remove an electron. Therefore, ionization energy is in indicator of reactivity. Ionization energy is important because it can be used to help predict the strength of chemical bonds. Ionization, together with atomic and ionic radius, electronegativity, electron affinity, and metallicity, follows a trend on the periodic table of elements.