Chemistry Basic Concepts and Atomic Structure

Matter: Anything that has mass and occupies space.
Elements: Pure substances that cannot be broken down into simpler substances (e.g., Hydrogen, Oxygen).
Compounds: Substances formed when two or more elements chemically bond together (e.g., Water - H₂O).
Mixtures: Combinations of two or more substances that retain their individual properties (e.g., Saltwater).

Atoms: Basic units of matter, consisting of:
- Nucleus: Contains protons (positive charge) and neutrons (no charge).
- Electrons: Negatively charged particles orbiting the nucleus.
Atomic Number: Number of protons in an atom, determines the element.
Mass Number: Total number of protons and neutrons in an atom.

Ionic Bonds: Formed when electrons are transferred from one atom to another, creating charged ions.
Covalent Bonds: Formed when atoms share electrons.
Metallic Bonds: Bonds between metal atoms where electrons are shared in a "sea" of electrons.

Reactants: Substances that undergo a chemical change.
Products: Substances produced as a result of a chemical reaction.
Types of Reactions:
- Synthesis: Two or more reactants combine to form a single product.
- Decomposition: A single compound breaks down into two or more simpler substances.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: Exchange of ions between two compounds.

Solid: Definite shape and volume; particles are tightly packed.
Liquid: Definite volume but takes the shape of the container; particles are close but can move past each other.
Gas: No definite shape or volume; particles are far apart and move freely.

Acids: Substances that release hydrogen ions (H⁺) in solution; taste sour, turn blue litmus paper red.
Bases: Substances that release hydroxide ions (OH⁻) in solution; taste bitter, turn red litmus paper blue.
pH Scale: Measures acidity or basicity; ranges from 0 (acidic) to 14 (basic), with 7 being neutral.

Organization: Elements arranged by increasing atomic number; grouped into periods (rows) and groups (columns).
Metals, Nonmetals, Metalloids: Distinct categories based on properties.
Trends:
- Atomic Radius: Increases down a group, decreases across a period.
- Ionization Energy: Energy required to remove an electron; increases across a period, decreases down a group.

Mole: Unit for amount of substance; 1 mole = 6.022 x 10²³ particles.
Balanced Chemical Equations: Show conservation of mass; same number of each type of atom on both sides.
Conversions: Use molar mass to convert between grams, moles, and particles.

Dynamic Equilibrium: Rate of forward reaction equals rate of reverse reaction.
Le Chatelier's Principle: If a system at equilibrium is disturbed, it will shift to counteract the disturbance.

Hydrocarbons: Compounds made of carbon and hydrogen; classified as aliphatic (straight or branched chains) and aromatic (ring structures).
Functional Groups: Specific groups of atoms that determine the characteristics of organic compounds (e.g., -OH for alcohols, -COOH for carboxylic acids).

Personal Protective Equipment (PPE): Use goggles, gloves, and lab coats.
Proper Ventilation: Ensure work areas are well-ventilated.
Chemical Disposal: Follow guidelines for disposing of hazardous materials safely.

Matter is defined as anything possessing mass and occupying space.
Elements are pure substances that cannot be further broken down; examples include Hydrogen and Oxygen.
Compounds consist of two or more elements chemically bonded, such as Water (H₂O).
Mixtures involve two or more substances combined while retaining their individual properties, like Saltwater.

Atoms are the fundamental units of matter, composed of:
- Nucleus containing protons (positively charged) and neutrons (neutral).
Electrons are negatively charged particles orbiting around the nucleus.
Atomic Number indicates the number of protons in an atom, which identifies the element.
Mass Number is the total count of protons and neutrons within an atom.

Ionic Bonds arise from the transfer of electrons between atoms, resulting in charged ions.
Covalent Bonds occur when two atoms share electrons.
Metallic Bonds involve metal atoms sharing electrons within a "sea" of electrons.

Reactants are the substances that undergo change during a chemical reaction.
Products are the results of the chemical change.
Reaction Types include:
- Synthesis reactions combine multiple reactants into one product.
- Decomposition reactions break down a single compound into simpler substances.
- Single Replacement reactions involve one element substituting another in a compound.
- Double Replacement reactions involve an exchange of ions between two compounds.

Solids maintain a definite shape and volume, with particles closely packed.
Liquids have a definite volume but adapt to the shape of their container, with closely arranged particles that can move past one another.
Gases lack definitive shape or volume; particles are widely spaced and move freely.

Acids generate hydrogen ions (H⁺) in solution; they usually taste sour and turn blue litmus red.
Bases create hydroxide ions (OH⁻) in solution; they typically taste bitter and turn red litmus blue.
The pH Scale quantifies acidity/basicity, ranging from 0 (acidic) to 14 (basic) with 7 being neutral.

Elements are systematically arranged by increasing atomic number, organized into rows (periods) and columns (groups).
Metals, Nonmetals, and Metalloids represent distinct categories based on characteristic properties.
Atomic Radius increases down a group and decreases across a period.
Ionization Energy, the energy needed to remove an electron, increases across a period and decreases down a group.

A Mole is a measurement unit representing a specific quantity of substance (6.022 x 10²³ particles).
Balanced Chemical Equations reflect the conservation of mass, showing identical numbers of each atom type on both sides.
Molar mass can be used for conversions between grams, moles, and individual particles.

Dynamic Equilibrium occurs when the forward reaction rate equals the reverse reaction rate.
Le Chatelier's Principle states that if a system at equilibrium is disturbed, it adjusts to mitigate the change.

Hydrocarbons consist solely of carbon and hydrogen; they are categorized as aliphatic (straight or branched chains) or aromatic (ring structures).
Functional Groups, specific atom groups, define the properties of organic compounds (e.g., -OH indicates alcohols, -COOH denotes carboxylic acids).

Personal Protective Equipment (PPE) is essential; include goggles, gloves, and lab coats for safety.
Proper Ventilation is crucial; ensure that workspaces are adequately ventilated.
Chemical Disposal guidelines must be followed to safely dispose of hazardous substances.