Chemistry Overview

Definition: The science that studies the composition, structure, properties, and changes of matter.
Branches:
- Organic Chemistry: Study of carbon-containing compounds.
- Inorganic Chemistry: Study of inorganic compounds, typically those without carbon.
- Physical Chemistry: Examines the physical properties and behavior of matter.
- Analytical Chemistry: Focuses on the composition of materials and the development of tools to measure properties.
- Biochemistry: Study of chemical processes within and related to living organisms.

Atoms: Basic units of matter; consist of protons, neutrons, and electrons.
Molecules: Composed of two or more atoms bonded together.
Chemical Bonds:
- Ionic Bonds: Formed through the transfer of electrons from one atom to another.
- Covalent Bonds: Formed by sharing electrons between atoms.
- Metallic Bonds: Bonding between metal atoms involving a "sea of electrons".

Elements: Pure substances that cannot be broken down; organized in the periodic table by atomic number.
Groups/Families: Vertical columns that share similar properties (e.g., alkali metals, noble gases).
Periods: Horizontal rows indicating the number of electron shells.

Solid: Defined shape and volume; particles tightly packed.
Liquid: Defined volume but takes the shape of the container; particles are less tightly packed.
Gas: No defined shape or volume; particles are far apart and move freely.

Reactants: Substances that undergo change.
Products: Substances formed as a result of the reaction.
Types of Reactions:
- Synthesis: Combining of substances to form a more complex product.
- Decomposition: Breaking down of a compound into simpler products.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: Exchange of ions between two compounds.

Mole: A unit for amount of substance; 1 mole = 6.022 x 10²³ entities (Avogadro's number).
Molar Mass: Mass of one mole of a substance (g/mol).

Acids: Substances that donate protons (H⁺) in solution; turn blue litmus paper red.
Bases: Substances that accept protons or donate hydroxide ions (OH⁻); turn red litmus paper blue.
pH Scale: Measures acidity or alkalinity; ranges from 0 (acidic) to 14 (basic).

Reaction Rate: Speed at which reactants are converted to products.
Factors Affecting Rate:
- Concentration of reactants
- Temperature
- Presence of catalysts

Dynamic Equilibrium: Reactions occur at equal rates in both directions.
Le Chatelier's Principle: If a system at equilibrium is disturbed, it will adjust to minimize the disturbance.

Chemistry studies the composition, structure, properties, and changes of matter.
Organic Chemistry involves carbon-containing compounds, while Inorganic Chemistry focuses on compounds typically lacking carbon.
Physical Chemistry examines physical properties and behavior of matter.
Analytical Chemistry analyzes material composition and develops measurement tools.
Biochemistry explores chemical processes in and related to living organisms.

Atoms are the basic units of matter, made of protons, neutrons, and electrons.
Molecules are formed from two or more atoms bonded together.
Ionic Bonds occur through electron transfer, while Covalent Bonds involve shared electrons.
Metallic Bonds consist of metal atoms with a "sea of electrons" facilitating bonding.

Elements are pure substances listed in the periodic table by atomic number.
Groups or Families in the periodic table are vertical columns sharing similar properties (e.g., alkali metals, noble gases).
Periods are horizontal rows that indicate the number of electron shells present in the elements.

Solids have defined shapes and volumes, with tightly packed particles.
Liquids maintain a defined volume but adapt to the shape of their container, with less tightly packed particles.
Gases have no defined shape or volume; particles are far apart and move freely.

Reactants are substances that participate in reactions, while Products are formed as results.
Synthesis involves the combination of substances to create more complex products.
Decomposition refers to breaking down a compound into simpler components.
Single Replacement occurs when one element substitutes another in a compound.
Double Replacement involves an exchange of ions between two compounds.

A mole is a measurement unit for saying the amount of substance, defined as 6.022 x 10²³ entities (Avogadro's number).
Molar Mass refers to the mass of one mole of a substance, expressed in grams per mole (g/mol).

Acids donate protons (H⁺) in a solution and turn blue litmus paper red.
Bases accept protons or donate hydroxide ions (OH⁻), turning red litmus paper blue.
The pH scale quantifies acidity (0-14), where lower values indicate acidic solutions and higher values indicate basic ones.

The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed.
Enthalpy (ΔH) indicates the heat content within a system.
Entropy (ΔS) measures the level of disorder or randomness in a system.

Reaction Rate describes how quickly reactants transform into products.
Factors influencing reaction rates include reactant concentration, temperature, and the presence of catalysts.

Dynamic Equilibrium exists when reactions proceed at equal rates in both directions.
Le Chatelier's Principle states that if a system at equilibrium is disturbed, it will adjust to counteract the disturbance.

Personal protective equipment (PPE) should always be worn during experiments.
Follow correct procedures for chemical handling and disposal.
Familiarize yourself with Material Safety Data Sheets (MSDS) for chemical safety information.