The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.

Ionization energy trends. Ionization energy: period trend. First and second ionization energy. Electron affinity: period trend. Electronegativity. Electronegativity and bonding. Metallic nature. Periodic trends and Coulomb's law. Worked example: Identifying an element from successive ionization energies.

periodic table, in chemistry, the organized array of all the chemical elements in order of increasing atomic number —i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the "periodic law" in their properties, in which elements in the same column …

By convention, elements are organized in the periodic table, a structure that captures important patterns in their behavior. Devised by Russian chemist Dmitri Mendeleev (1834–1907) in 1869, the table places elements into columns— groups —and rows— periods —that share certain properties.

The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.

An element group is a vertical column on the periodic table. Atoms in a group share the same number of valence electrons. There are 18 element groups. An element period is a horizontal row on the periodic table. Atoms in a period have the same number of electron shells. There are 7 element periods.

Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups.

A period is a horizontal (left-to-right) row on the periodic table. Each period is given a numerical value, beginning with "1," which is assigned to the top row. The period number increases by one for every additional row, up to a maximum of 7. It is important to note that the final two "rows" of elements on the periodic table are not periods 8 ...

There are currently seven complete periods in the periodic table, comprising the 118 known elements. Any new elements will be placed into an eighth period; see extended periodic table. The elements are colour-coded below by their block: red for the s-block, yellow for the p-block, blue for the d-block, and green for the f-block. Period 1

There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons. Period 1 has only two elements (hydrogen and helium), while periods 2 and 3 have 8 elements.