Phase Changes and Chemical Symbols

Phase Changes

• Matter changes phase when heated or cooled, but the temperature remains constant during the phase change.
• The temperature at which a substance changes phase is a critical property for identification and purity determination.
• The melting point is used to assess the purity of substances.

Chemical Symbols

• Elements are represented by symbols.
• Symbols are derived from the Latin name of the element and typically consist of one or two letters.
• Lead, for example, is represented by the symbol Pb (derived from the Latin word "plumbum").

The Periodic Table

• The periodic table organizes elements based on their atomic number.
• Metals are located on the left side of the periodic table, while non-metals are positioned on the right.
• The border between metals and non-metals is occupied by semi-metals (metalloids).

Types of Matter

• Matter is classified into two primary categories: pure substances and mixtures.
• Pure substances encompass elements and compounds.
• Mixtures consist of two or more pure substances.

Types of Mixtures

• Homogeneous mixtures, also known as solutions, have a uniform composition throughout.
• Heterogeneous mixtures, which include suspensions and mechanical mixtures, exhibit non-uniform composition.

Separation Techniques

• Different techniques are used to separate mixtures based on their properties.
• Suspensions tend to separate naturally unless an emulsifier is present, as seen in the separation of oil and water.
• Distillation is a technique utilized to separate solutions based on the disparity in boiling points of the components.

Summary Diagram of Matter

• Matter can be categorized into:
  • Pure Substance
    • Element
    • Compound
  • Mixture
    • Homogeneous Mixture
    • Heterogeneous Mixture

Visual Representation

• Elements and compounds have distinct molecular arrangements, reflecting their composition and mixture types.

What is Matter?

• Matter is defined as anything that possesses mass and volume.
• All objects, except for energy, are considered matter.

Matter is Conserved

• The Law of Conservation of Matter states that matter cannot be created or destroyed during a chemical reaction.
• In chemical reactions, atoms rearrange, but the total mass of the reactants and products remains constant.

Illustration

• In chemical changes, mass is conserved. No matter the scale of the reaction, mass is neither gained nor lost.

States of Matter

• Matter exists in three common states:
  • Solid: particles are rigidly arranged in a regular pattern, vibrating in place.
  • Liquid: particles are free to move around, but not beyond each other.
  • Gas: particles can move freely in any direction.
• All matter can transition between these states by adding or removing energy.
• Plasma, a fourth state of matter, is a highly ionized gas composed of charged particles.

Phase Changes

• Matter can transition between the four common phases by adding or removing energy, a process called phase change.
• Each phase change is uniquely named, depending on whether energy is added or removed.

Energy Transfer Diagram

• Solid to Liquid: Melting

• Liquid to Gas: Vaporization

• Gas to Liquid: Condensation

• Liquid to Solid: Freezing

• Solid to Gas: Sublimation

• Gas to Solid: Deposition

• Gas to Plasma: Ionization

• Plasma to Gas: Deionization

• Diagrams illustrating the relationships between different states and phase changes can help visualize these processes.