Frequently Asked Questions

The periodic table is a systematic arrangement of all known chemical elements organized by their atomic number (number of protons). It was created by Dmitri Mendeleev in 1869 and shows recurring patterns in element properties. Elements in the same column (group) have similar chemical properties, while elements in the same row (period) have the same number of electron shells.

Elements are arranged by increasing atomic number from left to right and top to bottom. The table has 18 vertical columns called groups and 7 horizontal rows called periods. This arrangement reveals periodic trends in properties like atomic size, ionization energy, and electronegativity.

Elements are classified into several main categories: Metals (conduct electricity, malleable, lustrous), Nonmetals (poor conductors, brittle when solid), Metalloids (properties between metals and nonmetals), Noble Gases (chemically inert), Alkali Metals (highly reactive metals), Alkaline Earth Metals (reactive but less than alkali metals), Halogens (reactive nonmetals), and Transition Metals (form colorful compounds).

Each element shows several key numbers: Atomic Number (top) - number of protons in the nucleus, Element Symbol (center) - 1-2 letter abbreviation, Element Name (below symbol), and Atomic Mass (bottom) - average mass of all isotopes. Some periodic tables also show electron configuration and other properties.

Elements become radioactive when their atomic nuclei are unstable due to having too many protons and neutrons. These unstable nuclei decay over time, emitting radiation in the form of alpha particles, beta particles, or gamma rays. All elements with atomic numbers above 83 (Bismuth) are radioactive, and some lighter elements also have radioactive isotopes.

New elements are created in particle accelerators by bombarding heavy atomic nuclei with lighter particles at extremely high speeds. These superheavy elements are highly unstable and exist for only fractions of a second before decaying. Scientists must detect their decay products to confirm the creation of a new element.

Electron configuration describes how electrons are distributed in an atom's electron shells and orbitals. It's written using numbers and letters (like 1s² 2s² 2p⁶) that indicate which orbitals contain electrons. This configuration determines an element's chemical properties and bonding behavior.

Elements in the same group (vertical column) have the same number of electrons in their outermost shell, called valence electrons. Since valence electrons determine how atoms bond with other atoms, elements with the same number of valence electrons exhibit similar chemical properties and reactivity patterns.

As of 2024, there are 118 confirmed elements in the periodic table. The most recent additions were elements 113 (Nihonium), 115 (Moscovium), 117 (Tennessine), and 118 (Oganesson), which were officially named in 2016. Scientists continue to attempt creating even heavier elements.

Our interactive periodic table allows you to click on any element to see detailed information including atomic properties, electron configuration, common uses, and interesting facts. You can also search for elements by name or symbol, filter by element categories, and explore different aspects of chemistry through our educational content.