Chimie: Atomes et particules élémentaires

Syllabus

• This document is a syllabus for a Physics course, specifically focusing on the atom.
• The course version is 6.1, from November 2024.
• The syllabus is for Bachelor's Block 1.
• The author is P. D. Doumont.
• The institution offering the course is HELHa, Haute École Louvain en Hainaut.

Table of Contents

• The document has a detailed table of contents listing the topics covered in the course, including sections on atoms, atomic forces, isotopes, reactions, nuclear and more.

Atom

• Matter is composed of fundamental particles called elements.
• Elements combine to form minerals and living organisms.
• An element is a pure substance that can't be chemically broken down further.
• Carbon is a key element of life.
• Some elements (e.g., technetium, promethium) occur naturally, while others (e.g. plutonium) are created artificially.
• Each element is made up of tiny, identical particles called atoms.
• An atom's fundamental structure consists of a central nucleus surrounded by orbiting electrons.
• The nucleus contains protons and neutrons.
• Electrons orbit the nucleus in energy levels called orbitals.
• Atoms are predominantly empty space.

Atomic Size and Components

• Atomic size is approximately 0.1 nm.
• Nuclear size is roughly 1 fm.
• Proton mass ≈ 1.673 x 10⁻²⁷ kg.
• Neutron mass ≈ 1.675 x 10⁻²⁷ kg.
• Electron mass ≈ 9.109 x 10⁻³¹ kg.
• Electron mass is significantly smaller than proton/neutron mass.

Atomic Structure

• The atom's nucleus is positively charged and comprises protons and neutrons.
• Protons and electrons have equal and opposite charges.
• Neutrons have no charge.

Isotopes

• Isotopes are atoms of the same element.
• They have varying numbers of neutrons.

Atomic Forces

• Atomic forces are the various interactions that hold atoms and their components together.
• These include strong force, electromagnetic force, weak force, and gravity.
• The strong force is the strongest of these forces, but acts only over very short distances.
• Electromagnetic forces dominate the behavior of atoms and molecules
• The weak force is responsible for radioactive decay in isotopes.
• Gravitation is the weakest among the forces, but acts over long distances

Atomic Number and Mass Number

• The atomic number (Z) represents the number of protons in an atom.
• The mass number (A) is the total number of protons and neutrons in an atom.

Atomic Mass Unit (u)

• One atomic mass unit (u) is equal to 1/12 the mass of a carbon-12 atom.
• It's also equivalent to appr 1.6605 x 10⁻²⁷ kg