Chemistry Study: Periodic Trends, Electron Configuration, and Atomic Properties

As we move across a period from left to right, the atomic size generally decreases because the effective nuclear charge increases, pulling the valence electrons closer to the nucleus.

Ionization energy (IE) generally increases going up a group and decreases down a group, while electron affinity (EA) tends to decrease as we move left to right across a period and increase down a group.

Electronegativity generally increases from left to right across a period due to the increasing number of valence shell electrons, making atoms more likely to gain additional electrons to complete their outer shell.

The effective nuclear charge remains constant in the group with noble gas elements due to the full valence shell, which is a stable electron configuration.

The principal quantum number (n) and the effective nuclear charge (Zeff) are factors that influence the values of ionization energy (IE) and electron affinity (EA).

The periodic table arranges elements based on their atomic properties, such as atomic number, electron configuration, and electronegativity. Elements within the same group have similar chemical properties due to their identical electron configuration in the valence shell, while elements in the same period have increasing atomic number and decreasing atomic radius.

The filling order of electron shells follows the specific pattern: s, p, d, and f. This pattern is used to determine the electron configuration of an element, which is then used to classify the element into categories such as metals, non-metals, metalloids, transition metals, and inner transition metals based on their electronic structure and chemical properties.

Electronegativity is the ability of an atom to attract shared electrons in a chemical bond. Electronegativity generally increases from left to right across a period and decreases from top to bottom in a group. Elements with a large difference in electronegativity tend to form ionic bonds, while elements with a smaller difference in electronegativity form covalent bonds.

Elements in the same group of the periodic table have the same number of valence electrons and exhibit similar chemical properties. For example, alkali metals (Group 1) are highly reactive, while noble gases (Group 18) are generally unreactive. The placement of an element in a group determines its valence electron configuration, which in turn determines its chemical reactivity and the types of compounds it can form.

Periodic trends are the gradual changes in the physical and chemical properties of elements as you move across a period (row) or down a group (column) in the periodic table. Atomic radius generally decreases from left to right in a period and increases from top to bottom in a group. Ionization energy increases from left to right in a period and decreases from top to bottom in a group. Electron affinity generally increases from left to right in a period and decreases from top to bottom in a group. These trends are due to the changes in the number of protons and electrons in the atoms of the elements.