Chemistry Basics and Atomic Structure

Matter: Anything that has mass and takes up space.
Elements: Pure substances made of one type of atom.
Compounds: Substances formed from two or more different elements chemically bonded together.
Mixtures: Combinations of two or more substances that retain their individual properties.

Atom: Basic unit of matter, consisting of protons, neutrons, and electrons.
- 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, 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: Involves the pooling of electrons in a 'sea' of electrons.

Reactants: Substances that undergo a chemical change.
Products: Substances formed as a result of a chemical reaction.
Types of Reactions:
- Synthesis: Two or more substances combine to form one product.
- Decomposition: A single compound breaks down into two or more simpler products.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: The exchange of ions between two compounds.
- Combustion: A substance reacts with oxygen, producing heat and light, typically yielding CO2 and H2O.

Solids: Definite shape and volume; particles are closely packed.
Liquids: Definite volume but no definite shape; particles are close but can move freely.
Gases: No definite shape or volume; particles are far apart and move freely.
Plasma: Ionized gas with free-moving ions and electrons.

Groups: Vertical columns that share similar chemical properties.
Periods: Horizontal rows that indicate the energy levels of electrons.
Metals, Nonmetals, Metalloids: Classification based on properties.
- Metals: Good conductors, malleable, ductile.
- Nonmetals: Poor conductors, brittle, gain electrons during reactions.
- Metalloids: Have properties intermediate between metals and nonmetals.

Acids: Substances that release hydrogen ions (H+) in solution. (pH < 7)
- Properties: Sour taste, conduct electricity, turn blue litmus paper red.
Bases: Substances that release hydroxide ions (OH-) in solution. (pH > 7)
- Properties: Bitter taste, slippery feel, turn red litmus paper blue.
pH Scale: Measures the acidity or basicity of a solution from 0 to 14.

Exothermic Reactions: Release heat to the surroundings.
Endothermic Reactions: Absorb heat from the surroundings.
Enthalpy: Measure of total energy in a system, changes during a reaction indicate heat exchange.

Mole: A quantity equal to 6.022 x 10²³ particles (Avogadro's number).
Balanced Equation: Represents a chemical reaction with equal numbers of atoms for each element on both sides.
Concentration: Amount of solute per unit volume of solution (molarity).

Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction.
Chemical Equilibrium: A state where reactants and products are formed at the same rate.
Catalysts: Substances that speed up a chemical reaction without being consumed.

Always wear appropriate personal protective equipment (PPE) such as gloves, goggles, and lab coats.
Understand the properties of the chemicals you are working with, including toxicity, flammability, and reactivity.
Follow proper waste disposal procedures for chemicals.

Matter comprises anything with mass and occupies space.
Elements are pure substances containing only one type of atom.
Compounds, formed through chemical bonding of two or more different elements, exhibit properties distinct from their constituent elements.
Mixtures consist of two or more substances that maintain their individual characteristics.

Atoms are the fundamental units of matter, made up of protons, neutrons, and electrons.
Protons carry a positive charge and are located in the nucleus.
Neutrons, which have no charge, also reside in the nucleus.
Electrons are negatively charged and orbit the nucleus in defined energy levels.
The atomic number indicates the number of protons, defining the element.
Mass number represents the total count of protons and neutrons in an atom.

Ionic bonds occur when electrons are transferred between atoms, resulting in charged ions.
Covalent bonds form when atoms share electrons, creating stable molecular structures.
Metallic bonds feature a 'sea' of delocalized electrons that allows for conductivity and malleability.

Reactants are the starting substances in a chemical reaction.
Products result from the transformation of reactants through chemical processes.
Synthesis reactions involve the combination of substances to form a single product.
Decomposition reactions break down a compound into simpler substances.
Single replacement reactions occur when one element displaces another in a compound.
Double replacement reactions involve the exchange of ions between two compounds.
Combustion reactions combine a substance with oxygen, often yielding carbon dioxide and water while releasing heat and light.

Solids possess a definite shape and volume, with tightly packed particles.
Liquids maintain a constant volume but take the shape of their container, with closely packed yet mobile particles.
Gases lack a fixed shape or volume, featuring widely spaced particles that move freely.
Plasma consists of ionized gas with free-moving ions and electrons, typically found in stars.

Groups, or vertical columns, group elements with similar chemical properties.
Periods are horizontal rows indicating the number of electron energy levels.
Elements may be categorized as metals, nonmetals, or metalloids based on their properties.
Metals exhibit good conductivity, malleability, and ductility.
Nonmetals are generally poor conductors, brittle, and tend to gain electrons in reactions.
Metalloids display properties intermediate between metals and nonmetals.

Acids generate hydrogen ions (H+) in solution, characterized by a pH less than 7.
- They taste sour, conduct electricity, and turn blue litmus paper red.
Bases produce hydroxide ions (OH-) in solution, with a pH greater than 7.
- Bases have a bitter taste, slippery texture, and turn red litmus paper blue.
The pH scale evaluates the acidity or basicity of solutions, ranging from 0 to 14.

Exothermic reactions expel heat, raising the temperature of surroundings.
Endothermic reactions absorb heat, leading to a drop in environmental temperature.
Enthalpy measures total energy within a system, with changes denoting heat exchange during reactions.

A mole represents a quantity of 6.022 x 10²³ particles, known as Avogadro's number.
A balanced equation maintains equal numbers of each type of atom on both sides of a chemical reaction.
Concentration describes the amount of solute in a given volume of solution, typically expressed in molarity.

The Law of Conservation of Mass states that mass remains constant in chemical reactions—neither created nor destroyed.
Chemical equilibrium is achieved when reactants and products convert at matching rates.
Catalysts enhance reaction rates without being consumed in the process.

Always utilize personal protective equipment (PPE), including gloves, goggles, and lab coats.
Familiarize yourself with the properties of chemicals, focusing on their toxicity, flammability, and reactivity.
Adhere to proper waste disposal protocols for all chemicals used in experiments.