Basic Concepts of Chemistry

Atoms: Basic unit of matter, consists of protons, neutrons, and electrons.
Elements: Pure substances made of only one type of atom (e.g., Hydrogen, Oxygen).
Compounds: Substances formed when two or more elements chemically bond (e.g., H2O, CO2).

Solid: Definite shape and volume; particles are tightly packed.
Liquid: Definite volume but no definite shape; particles are close but can move past one another.
Gas: No definite shape or volume; particles are far apart and move freely.

Ionic Bonds: Formed when electrons are transferred from one atom to another; typically between metals and nonmetals.
Covalent Bonds: Formed when atoms share electrons; typically between nonmetals.
Metallic Bonds: Involve a pooling of electrons among a lattice of metal atoms.

Reactants: Substances present before a chemical reaction.
Products: Substances formed as a result of a chemical reaction.
Types of Reactions:
- Synthesis: Two or more substances combine to form a new compound.
- Decomposition: A compound breaks down into simpler products.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: Exchange of ions between two compounds.

Relates to the quantitative relationships between reactants and products in a chemical reaction.
Mole: A unit to measure quantity in chemistry; one mole equals 6.022 x 10²³ entities (Avogadro's number).

Acids: Substances that donate protons (H⁺) in solution, typically have a sour taste, and turn litmus paper red.
Bases: Substances that accept protons or donate hydroxide ions (OH⁻), typically have a bitter taste, and turn litmus paper blue.
pH Scale: Measures the acidity or basicity of a solution (0-14 scale); 7 is neutral, below 7 is acidic, above 7 is basic.

Organized by atomic number, groups (columns) have similar properties, periods (rows) show increasing atomic number.
Metals: Located on the left side; usually good conductors of heat and electricity.
Nonmetals: Located on the right side; generally poor conductors and more variable in properties.
Metalloids: Found along the "stair-step" line; exhibit properties of both metals and nonmetals.

Study of carbon-containing compounds.
Functional Groups: Specific groups of atoms responsible for the characteristic reactions of those molecules (e.g., hydroxyl -OH, carboxyl -COOH).

Titration: Technique to determine concentration of a solution by adding a reaction from a solution of unknown concentration until reaction completion.
Chromatography: Method for separating components in a mixture based on their movement through a stationary phase.
Spectroscopy: Technique to study interactions between matter and electromagnetic radiation.

The fundamental building block of matter is the atom, composed of protons, neutrons, and electrons.
A pure substance consisting solely of one type of atom is called an element. Examples include hydrogen (H) and oxygen (O).
When two or more elements chemically combine in a fixed ratio, they form a compound. Water (H₂O) and carbon dioxide (CO₂) are common examples.

Solids possess a definite shape and volume due to their tightly packed particles.
Liquids maintain a definite volume but lack a fixed shape because their particles are close together but can move freely.
Gases exhibit neither a fixed shape nor volume, as their particles are widely spaced and move randomly.

Ionic bonds arise from the transfer of electrons between atoms, typically involving a metal and a nonmetal.
Covalent bonds involve the sharing of electrons between atoms, usually occurring between nonmetals.
Metallic bonds result from a collective pooling of electrons within a lattice of metal atoms.

Reactants are the substances present before a chemical change occurs.
Products are the newly formed substances after a chemical reaction takes place.
Types of Reactions:
- Synthesis: Two or more substances combine to form a single compound.
- Decomposition: A compound breaks down into simpler substances.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: Two compounds exchange ions with each other.

Stoichiometry deals with the quantitative relationships between reactants and products in chemical reactions.
The mole is a commonly used unit in chemistry to represent the amount of substance. One mole contains 6.022 x 10²³ entities, known as Avogadro's number.

Acids are substances that donate protons (H⁺) in solution. They typically taste sour and turn litmus paper red.
Bases accept protons or donate hydroxide ions (OH⁻). They usually taste bitter and turn litmus paper blue.
The pH scale quantifies the acidity or basicity of a solution. A pH value of 7 is neutral, values below 7 indicate acidity, and values above 7 indicate basicity.

The periodic table organizes elements by increasing atomic number. Elements in the same group (column) have similar properties, and elements in the same period (row) exhibit increasing atomic number.
Metals occupy the left side of the periodic table and are typically good conductors of heat and electricity.
Nonmetals are located on the right side of the periodic table and generally exhibit poor conductivity and more diverse properties.
Metalloids reside along the "stair-step" line separating metals and nonmetals and possess characteristics of both metals and nonmetals.

Thermochemistry studies heat changes associated with chemical reactions.
Endothermic reactions absorb heat from the surroundings (e.g., photosynthesis).
Exothermic reactions release heat into the surroundings (e.g., combustion).

Organic chemistry centers on the study of carbon-containing compounds.
Functional groups are specific groups of atoms within molecules that define their reactivity and properties. Examples include the hydroxyl group (-OH) and the carboxyl group (-COOH).

Inorganic chemistry explores compounds that do not contain carbon, excluding organic compounds. This area encompasses metals, minerals, and organometallic compounds.

Titration is a method used to determine the concentration of a solution by gradually adding a reagent of known concentration until a reaction endpoint is reached.
Chromatography separates components in a mixture based on their varying movement through a stationary phase.
Spectroscopy employs the interaction between matter and electromagnetic radiation to study its properties.

Always wear safety goggles, gloves, and a lab coat in the lab.
Learn the location of safety equipment, such as eyewash stations and fire extinguishers.
Dispose of chemical waste responsibly, following established regulations.