Introducción a la Materia

Introduction to Matter

• Matter is anything that occupies space and has mass.
• It exists in various forms, including solid, liquid, and gas.
• Matter is composed of fundamental units called atoms.
• Atoms are composed of subatomic particles: protons, neutrons, and electrons.

States of Matter

• Solid: Has a fixed shape and volume. Particles are tightly packed and vibrate in place.
• Liquid: Has a definite volume but takes the shape of its container. Particles are close together but can move past each other.
• Gas: Has neither a fixed shape nor a fixed volume. Particles are widely spaced and move freely in all directions.
• Plasma: A superheated state of matter where electrons are stripped from atoms, creating an electrically charged gas.

Properties of Matter

• Mass: The amount of matter in an object. Measured in grams (g) or kilograms (kg).
• Volume: The amount of space an object occupies. Measured in cubic centimeters (cm³) or liters (L).
• Density: Mass per unit volume. (Density = Mass/Volume) Often expressed in g/cm³ or kg/m³.
• Temperature: A measure of the average kinetic energy of the particles in a substance. Measured in Celsius (°C), Fahrenheit (°F), or Kelvin (K).
• Melting Point: The temperature at which a solid changes to a liquid.
• Boiling Point: The temperature at which a liquid changes to a gas.
• Conductivity: The ability of a substance to conduct heat or electricity.
• Malleability: The ability of a substance to be hammered or rolled into thin sheets.
• Ductility: The ability of a substance to be drawn into wires.

Changes in Matter

• Physical Change: A change in the form or appearance of matter without changing its chemical composition. Examples include: melting, freezing, boiling, vaporization, condensation, sublimation, and dissolving.
• Chemical Change: A change that results in the formation of one or more new substances with different properties. Examples include combustion, oxidation, and decomposition.

Elements and Compounds

• Elements: Pure substances that cannot be broken down into simpler substances by chemical means. Each element is made of one type of atom.
• Compounds: Pure substances formed from two or more elements chemically combined in a fixed ratio. Compounds have different properties than the elements they are composed of.

Mixtures

• Homogeneous mixtures: Mixtures that have a uniform composition throughout. Example: saltwater solution.
• Heterogeneous mixtures: Mixtures that do not have a uniform composition throughout. Example: sand in water.

Atomic Structure

• Atoms are composed of a nucleus containing protons and neutrons, and electrons orbiting the nucleus.
• Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.
• Atomic number represents the number of protons in an atom.
• Atomic mass represents the total number of protons and neutrons in an atom.

Periodic Table

• A table that organizes all known elements based on their properties.
• Elements are arranged in rows (periods) and columns (groups) based on their atomic structure and properties.
• Elements in the same group have similar chemical properties.

Molecular Structure

• Molecules are groups of two or more atoms held together by chemical bonds.
• Different types of bonds (ionic, covalent, metallic) determine the properties of molecules.
• Molecular structure affects the properties of substances, including their shape and reactivity.