Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Models of the Atom: Structure and Bonding

In course

BIO-109: Introduction to life sciences (for IC)

Ce cours présente les principes fondamentaux à l'œuvre dans les organismes vivants. Autant que possible, l'accent est mis sur les contributions de l'Informatique aux progrès des Sciences de la Vie. ...

Description

This lecture covers the historical development of atomic models from the Greek model to the charge-cloud model. It explains the concepts of atomic number, atomic mass, ionization, and covalent bonding. The lecture also discusses the polar nature of covalent bonds and properties of water related to polarity.

Instructor

Romain Zufferey

Official source

Related concepts (32)

Atomic number

The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used to uniquely identify ordinary chemical elements. In an ordinary uncharged atom, the atomic number is also equal to the number of electrons.

Covalent bond

A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full valence shell, corresponding to a stable electronic configuration. In organic chemistry, covalent bonding is much more common than ionic bonding.

Mass number

The mass number (symbol A, from the German word: Atomgewicht, "atomic weight"), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is approximately equal to the atomic (also known as isotopic) mass of the atom expressed in atomic mass units. Since protons and neutrons are both baryons, the mass number A is identical with the baryon number B of the nucleus (and also of the whole atom or ion).

Atomic mass

The atomic mass (ma or m) is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1 Da is defined as of the mass of a free carbon-12 atom at rest in its ground state. The protons and neutrons of the nucleus account for nearly all of the total mass of atoms, with the electrons and nuclear binding energy making minor contributions.

Coordinate covalent bond

In coordination chemistry, a coordinate covalent bond, also known as a dative bond, dipolar bond, or coordinate bond is a kind of two-center, two-electron covalent bond in which the two electrons derive from the same atom. The bonding of metal ions to ligands involves this kind of interaction. This type of interaction is central to Lewis acid–base theory. Coordinate bonds are commonly found in coordination compounds. Coordinate covalent bonding is ubiquitous.

Related lectures (30)

Periodic Table and Stoichiometry

Covers the periodic table, atomic properties, isotopes, stoichiometry, and chemical reactions, explaining their relationships and principles.

Chemistry: Atomic Structure and Thermodynamics

Covers atomic structure, thermodynamics, material properties, and ideal gas law.

Atomic Structure: Electronic Configuration

Explores atomic structure, electron configuration, periodic trends, and chemical properties in atoms.

Chemical Bond: Periodic Trends and Lewis Structure

Explores chemical bond, periodic trends, Lewis structure, and bond polarity.

Chemical Bonds and Reactions