3. Atoms and Molecules

  • 3

    Atoms And Molecules

    The section discusses the foundational concepts of atoms and molecules, including the laws of conservation of mass and constant proportions, and introduces Dalton's atomic theory.

  • 3.1

    Laws Of Chemical Combination

    The section discusses the fundamental laws governing chemical combinations, namely the Law of Conservation of Mass and the Law of Constant Proportions.

  • 3.1.1

    Law Of Conservation Of Mass

    The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction.

  • 3.1.2

    Law Of Constant Proportions

    The Law of Constant Proportions states that in a chemical compound, elements combine in fixed ratios by mass.

  • 3.2

    What Is An Atom?

    This section introduces the concept of atoms as the fundamental building blocks of matter, detailing their properties, symbols, and significance in chemical reactions.

  • 3.2.1

    What Are The Modern Day Symbols Of Atoms Of Different Elements

    This section discusses the historical development and modern representation of atomic symbols for different elements.

  • 3.2.2

    Atomic Mass

    This section discusses the concept of atomic mass and highlights its significance in atomic theory.

  • 3.2.3

    How Do Atoms Exist

    Atoms of most elements cannot exist independently; they form molecules or ions that aggregate to create matter.

  • 3.3

    What Is A Molecule?

    A molecule is defined as a group of two or more atoms that are chemically bonded together, representing the smallest particle of an element or compound capable of independent existence.

  • 3.3.1

    Molecules Of Elements

    This section explains the concept of molecules, particularly focusing on how elements are composed of molecules formed from the same type of atoms.

  • 3.3.2

    Molecules Of Compounds

    Compounds are formed when atoms of different elements combine in fixed proportions, resulting in unique chemical structures and properties.

  • 3.3.3

    What Is An Ion?

    This section discusses the concept of ions in compounds formed from metals and non-metals, expounding on the terms anions, cations, and polyatomic ions.

  • 3.4

    Writing Chemical Formulae

    This section introduces the rules for writing chemical formulae of compounds based on the valencies and combinations of elements.

  • 3.4.1

    Formulae Of Simple Compounds

    This section explains the concept of binary compounds, their valency, and how to write chemical formulae for simple compounds.

  • 3.5

    Molecular Mass

    Molecular Mass refers to the sum of the atomic masses of all atoms in a molecule, expressed in atomic mass units (u).

  • 3.5.1

    Molecular Mass

    This section introduces the concept of molecular mass, explaining how it can be calculated by summing the atomic masses of the atoms present in a molecule.

  • 3.5.2

    Formula Unit Mass

    This section introduces the concept of formula unit mass, explaining how to calculate it and its relationship with molecular mass.