Periodic Table & Atomic Structure
- Title
- Periodic Table & Atomic Structure
- Description
Periodic Table & Atomic Structure
The periodic table is a tabular display of all known chemical elements, organized by atomic number and chemical properties.
Atomic Structure
- Composition: An atom consists of a central nucleus (protons and neutrons) surrounded by electrons.
- Particles: Protons (positive charge), Neutrons (no charge), and Electrons (negative charge).
- Definitions: Atomic number = number of protons; Mass number = protons + neutrons.
The Periodic Table
- History: Arranged by Dmitri Mendeleev in 1869.
- Scale: Contains 118 confirmed elements (as of 2024).
- Organization: Elements are arranged in Periods (rows) and Groups (columns) based on properties.
- Key Groups:
- Noble Gases (Group 18): Includes He, Ne, Ar, Kr, Xe, Rn; largely unreactive.
- Alkali Metals (Group 1): Highly reactive with water.
- Category
- Chemistry
- Year of Discovery/Development
- 1869
- Key Person/Organization
- Dmitri Mendeleev