Fundamentals of Science: Physics, Chemistry, and Matter Properties

Science Fundamentals

Definition of Science

Science: Is defined as a body of knowledge about the world obtained through observation, experimentation, and razonamiento (reasoning), which follows laws from which testable theories are built.

Branches of Science

• Física (Physics): The science dealing with any change in this area where there is no change in the nature of the substance itself.
• Química (Chemistry): The science that studies the composition, combination, and transformation of substances that affect nature.

Properties of Matter

General Properties

Those whose value does not identify a specific substance. Mass, volume, and the temperature at which a body is found are general properties.

Characteristic Properties

Those that have their own value and characteristic for each substance. Density, melting point, boiling point, hardness, water solubility, and electrical conductivity are characteristic properties.

Measurement Concepts

Magnitude

Call a magnitude any feature of matter, or changes that may occur, which can be measured; that is, it is possible to express it with a number and a unit.

Unit

Measuring a magnitude is to compare it with one of its own kind, which we call a unit, to see how many times it is contained.

Gas Laws

• Boyle-Mariotte Law: P₁ × V₁ = P₂ × V₂
• Gay-Lussac's Law (Pressure-Temperature): P₁/T₁ = P₂/T₂
• Charles and Gay-Lussac's Law (Volume-Temperature): V₁/T₁ = V₂/T₂

States of Matter

• Solid: Steady, constant volume, does not expand, is not compressed (e.g., ice, sugar, marble).
• Liquid: Variable shape, constant volume, does not expand, compressed with difficulty (e.g., water, oil, alcohol).
• Gas: Variable shape, variable volume, expands, is compressed (e.g., steam, air).

Phase Changes

• Solid to Liquid: Fusion.
• Liquid to Solid: Solidification.
• Solid to Gas: Sublimation.
• Gas to Solid: Inverse Sublimation (Deposition).
• Liquid to Gas: Vaporization.
• Gas to Liquid: Liquefaction.

Classification of Substances

Pure Substances

• Pure Substance: Matter whose composition does not change whatever the physical conditions are.
• Compounds: They are pure substances that can be decomposed into simpler ones through a chemical process.
• Elements: They are pure substances that cannot be decomposed into simpler ones by any procedure.

Mixtures

A mixture is material resulting from the combination of several pure substances that can be separated using physical means.

• Heterogeneous: A mixture in which one can distinguish components optically or by other procedures.
• Homogeneous: A mixture in which no distinction between components is possible by conventional procedures.

Dalton's Atomic Theory

Dalton

Matter is made of atoms, which are indivisible and indestructible particles. All atoms of the same chemical element are equal in mass and properties, and atoms of any element differ from atoms of any other element. Compounds are formed by combinations of atoms of diverse elements.

Examples of States

Gas Examples

Gas, air.

Liquid Examples

Refreshing drinks (liquid), water and alcohol (liquid).

Solid Examples

Solid, alloys (solid).