Properties and States of Matter

Properties of Matter

• Substances are described by properties, classified as physical or chemical.
• Physical properties are observed without changing the substance's identity (reversible changes).
  • Examples: color, hardness, conductivity, density.
• Physical properties can be intensive (independent of quantity) or extensive (dependent on quantity).
  • Examples: odor (intensive), volume (extensive).
• Chemical properties describe how a substance reacts with others.
  • Examples: tendency to combine with other substances, change color, or release heat.

States of Matter

• Matter exists as solids, liquids, and gases.
• Solids: atoms are closely packed, fixed position, definite shape and volume.
• Liquids: atoms are loosely bonded, indefinite shape, definite volume.
• Gases: atoms move freely, indefinite shape and volume, compressible.
• Phase changes involve changes between states:
  • Melting (solid to liquid): increase in energy/temperature.
  • Freezing (liquid to solid): decrease in temperature.
  • Vaporization (liquid to gas): addition of energy.
  • Condensation (gas to liquid): cooling of vapor.

Atoms and Elements

• Atoms are the fundamental building blocks of matter.
  • Composed of a nucleus (protons and neutrons) and electron cloud.
• Subatomic particles:
  • Protons: positive charge, located in nucleus.
  • Neutrons: neutral charge, located in nucleus.
  • Electrons: negative charge, located in electron cloud.
• Atoms are too small to see directly, understood through models.
• Elements are different types of atoms with unique properties; defined by the number of protons.

The Periodic Table

• The periodic table organizes all known elements.
• Each element has an atomic number (number of protons).
• Elements' characteristics are determined by their atomic number, how they might interact with other elements.

Isotopes

• Isotopes are different forms of an element with the same number of protons and electrons but different numbers of neutrons.
• Isotopes are characterized by their atomic masses.
• Stable isotopes have stable ratios of protons and neutrons.
• Radioactive isotopes are unstable and undergo radioactive decay.
• Isotopic abundance is the relative amount of each isotope in nature. Measured using mass spectrometry.

Ions

• Ions form when atoms gain or lose electrons, creating a charge.
  • Cations: positive ions (lose electrons).
  • Anions: negative ions (gain electrons).
• Ions can be single atoms, molecules, or larger groups.
• Monoatomic ions: ions consisting of one atom
• Polyatomic ions: ions consisting of multiple atoms.
• Ionic bonds form between metals and nonmetals. Covalent bonds form between nonmetals.

Types of Compounds

• Compounds can be ionic or covalent.
• Ionic compounds: formed by the attraction between positively charged metal cations and negatively charged nonmetal anions.
• Covalent compounds: formed by sharing electrons between nonmetal atoms.

Mixtures and Pure Substances

• Mixtures can be separated without changing their chemical composition.
• Pure substances:
  • Elements are made from one type of atom.
  • Compounds have two or more different types of atoms in a fixed ratio.

Chemical Bonds

• Two main types of bonds:
  • Ionic bonds: transfer of electrons between atoms.
  • Covalent bonds: sharing of electrons between atoms.
  • Metallic bonds: in metals, electrons move freely between atoms.
    • Polar covalent bonds: electrons are shared unevenly between atoms.
    • Non-polar covalent bonds: electrons are shared equally between atoms.
• Hydrogen bonds: attractive forces between a hydrogen atom and another strongly electronegative atom(like oxygen or nitrogen).

This quiz explores the fundamental concepts of matter, including its properties and states. Learn about physical and chemical properties, as well as the characteristics of solids, liquids, and gases. Test your understanding of phase changes and the behavior of substances.