Introduction to Chemistry

Study Notes

Matter exists in four distinct states: gas, liquid, solid, and plasma.
States are determined by particle arrangement, movement, and the strength of intermolecular forces.
Energy influences state changes: heating solids turns them into liquids or gases; high temperatures or strong electric fields can convert gases into plasma.
Crystalline solids can become cloudy liquids known as liquid crystals, which exhibit properties of both solids and liquids within a certain temperature range.
Bose-Einstein Condensates (BEC) occur at near absolute zero temperatures, observable under extreme conditions, and include superfluids and superconductors.

Macroscopic properties include density, fluidity, and compressibility.
Density varies across states: gases have low density, liquids and solids have high density.
Compressibility differs: gases are highly compressible, liquids moderately, and solids are not compressible.
Fluidity is present in gases and liquids, but solids cannot flow.

States of matter can be transformed through physical techniques (temperature/pressure adjustments) without altering chemical composition.
Observations during boiling (like water forming bubbles) exemplify state changes.

Matter can be classified into pure substances (elements and compounds) or mixtures.
Elements: Simplest form of matter with atoms having the same atomic number (proton number); cannot be chemically broken down.
Compounds: Substances formed when two or more different elements chemically combine, resulting in new properties.
Mixtures: Physical combinations of substances; can be homogeneous (uniform) or heterogeneous (non-uniform).
- Examples of heterogeneous mixtures include colloids and suspensions.

Allotropes are different physical forms of the same element, with atoms arranged differently.
Carbon allotropes include diamond, graphite, and buckyballs.
Graphite: Contains two-dimensional layers of hexagonally arranged carbon atoms, bonded covalently within layers and held by weak intermolecular forces, allowing the layers to slide over one another.