Basic Concepts of Chemistry

Matter: Anything that has mass and occupies space.
Elements: Pure substances that cannot be broken down. Consist of atoms (e.g., hydrogen, oxygen).
Compounds: Substances formed from two or more elements chemically combined (e.g., water (H₂O), carbon dioxide (CO₂)).

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

Atom: Basic unit of matter, consisting of:
- Protons: Positively charged particles in the nucleus.
- Neutrons: Neutral particles in the nucleus.
- Electrons: Negatively charged particles orbiting the nucleus.
Atomic Number: Number of protons in an atom; defines the element.
Mass Number: Total number of protons and neutrons in the nucleus.

Ionic Bonds: Formed when electrons are transferred from one atom to another, creating charged ions (e.g., NaCl).
Covalent Bonds: Formed when two atoms share electrons (e.g., H₂, O₂).
Metallic Bonds: Involves the sharing of free electrons among a lattice of metal atoms.

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

Acids: Substances that donate protons (H⁺) in a reaction; have a pH less than 7 (e.g., hydrochloric acid (HCl)).
Bases: Substances that accept protons; have a pH greater than 7 (e.g., sodium hydroxide (NaOH)).
pH Scale: Measures how acidic or basic a solution is, ranging from 0 (strongly acidic) to 14 (strongly basic).

Groups: Vertical columns; elements in the same group have similar chemical properties.
Periods: Horizontal rows; properties change progressively across a period.
Metals, Nonmetals, Metalloids: Classification based on physical and chemical properties.

Mole: A unit that represents 6.022 x 10²³ particles (Avogadro's number).
Molar Mass: The mass of one mole of a substance, expressed in grams per mole (g/mol).
Balancing Equations: Ensures the same number of each type of atom on both sides of a chemical reaction.

Endothermic Reactions: Absorb heat from the surroundings (e.g., photosynthesis).
Exothermic Reactions: Release heat to the surroundings (e.g., combustion).

Hydrocarbons: Compounds made of carbon and hydrogen (e.g., alkanes, alkenes, alkynes).
Functional Groups: Specific groups of atoms that give compounds characteristic properties (e.g., -OH in alcohols, -COOH in carboxylic acids).

Titration: Technique to determine concentration of a solution by reacting it with a standard solution.
Chromatography: Method for separating mixtures based on different interactions with a stationary phase.
Spectroscopy: Technique used to identify substances based on their interaction with light.

Personal Protective Equipment (PPE): Use of goggles, gloves, and lab coats.
Chemical Storage: Proper labeling and storage of chemicals to avoid reactions.
Emergency Procedures: Knowing how to respond to spills, fires, and exposures.

Matter encompasses anything with mass and volume.
Elements are the simplest forms of matter, consisting of atoms that cannot be broken down further (e.g., hydrogen (H), oxygen (O)).
Compounds consist of two or more elements that are chemically bonded, like water (H₂O) and carbon dioxide (CO₂).

Solid: Retains a fixed shape and volume; particles are tightly packed.
Liquid: Maintains a fixed volume but adapts to the shape of its container; particles are less densely packed than in solids.
Gas: Lacks a fixed shape or volume; particles are widely spaced and move freely.

Atoms are the fundamental units of matter composed of:
- Protons: Positively charged, located in the nucleus.
- Neutrons: Neutral particles also found in the nucleus.
- Electrons: Negatively charged, orbit the nucleus at varying energy levels.
Atomic Number indicates the number of protons in an atom, defining its elemental identity.
Mass Number represents the total count of protons and neutrons in the nucleus.

Ionic Bonds arise from the transfer of electrons between atoms, resulting in charged ions (e.g., sodium chloride (NaCl)).
Covalent Bonds involve the sharing of electrons between atoms (e.g., hydrogen gas (H₂), oxygen gas (O₂)).
Metallic Bonds feature the delocalization of electrons among a lattice of metal ions.

Reactants are the initial substances that undergo transformation in a reaction.
Products are the resultant substances formed during a chemical reaction.
Types of Reactions include:
- Synthesis: Combining multiple reactants to form a single product.
- Decomposition: A single compound breaking down into multiple products.
- Single Replacement: An element within a compound is replaced by another element.
- Double Replacement: Ions are exchanged between two compounds.

Acids donate protons (H⁺) in chemical reactions and have a pH below 7, such as hydrochloric acid (HCl).
Bases accept protons and have a pH above 7, such as sodium hydroxide (NaOH).
The pH Scale measures the acidity or basicity of a solution on a scale from 0 (strongly acidic) to 14 (strongly basic).

Groups represent vertical columns containing elements with similar properties.
Periods are horizontal rows where properties vary progressively across the table.
Elements are classified into Metals, Nonmetals, and Metalloids based on their physical and chemical characteristics.

A Mole is a quantity equivalent to 6.022 x 10²³ particles (Avogadro's number).
Molar Mass is the mass of one mole of a substance expressed in grams per mole (g/mol).
Balancing Equations ensures that the number of atoms of each element remains constant during a chemical reaction.

Endothermic Reactions absorb heat from their surroundings, such as in photosynthesis.
Exothermic Reactions release heat, commonly observed in combustion processes.

Hydrocarbons are organic compounds made of carbon and hydrogen, including alkanes, alkenes, and alkynes.
Functional Groups are specific groups of atoms that impart unique chemical properties to compounds, like -OH in alcohols and -COOH in carboxylic acids.

Titration is used to determine the concentration of a solution by reacting it with a standard solution.
Chromatography separates mixtures based on their interactions with a stationary phase.
Spectroscopy identifies substances through their interactions with light.

Personal Protective Equipment (PPE) includes goggles, gloves, and lab coats to ensure safety.
Chemical Storage requires proper labeling and secure storage of chemicals to prevent hazardous reactions.
Emergency Procedures must be understood to effectively respond to spills, fires, or chemical exposures.