Structure of Atoms and Ions in Chemistry
This page provides an overview of atomic structure and the formation of ions, which are fundamental concepts in chemistry. It also introduces the periodic table as a tool for organizing elements based on their atomic properties.
The page begins by explaining that everything is composed of atoms, which are incredibly small particles. A single cell may contain around 1 trillion atoms, emphasizing their minuscule size.
Definition: An atom is the smallest unit of matter that retains the properties of an element.
The structure of an atom is described as having a central nucleus surrounded by orbiting electrons. The nucleus contains protons and neutrons packed tightly together, while electrons move around the nucleus in shells.
Highlight: Most of an atom is empty space, with the nucleus being about 10,000 times smaller than the atom's radius.
The page then discusses the formation of ions:
Definition: Ions are atoms that have gained or lost electrons, resulting in a net electrical charge.
- If an atom gains electrons, it forms a negatively charged ion.
- If an atom loses electrons, it forms a positively charged ion.
Key concepts about atomic structure are presented:
- The atomic number is equal to the number of protons in an atom.
- The mass number is the total number of protons and neutrons.
- In a neutral atom, the number of protons equals the number of electrons.
Example: The periodic table entry for Lithium (Li) shows:
- Atomic number: 3 (number of protons)
- Mass number: 7 (total protons and neutrons)
- Relative atomic mass: 6.94 (average mass of all isotopes)
The page includes a detailed periodic table, highlighting the arrangement of elements based on their atomic structure. Each element's entry provides the atomic number, symbol, and relative atomic mass.
Vocabulary:
- Proton: Positively charged particle in the nucleus
- Neutron: Neutral particle in the nucleus
- Electron: Negatively charged particle orbiting the nucleus
The bottom of the page features a table summarizing the properties of protons, neutrons, and electrons:
| Particle | Charge | Mass (amu) | Location |
|----------|--------|------------|----------|
| Proton | +1 | 1 | Nucleus |
| Neutron | 0 | 1 | Nucleus |
| Electron | -1 | 1/1836 | Orbitals |
This comprehensive overview provides students with a solid foundation for understanding atomic structure, isotopes, and ion formation, which are crucial concepts in chemistry.
