Chemistry Basics and Atomic Structure

Matter: Anything that has mass and occupies space.
Atoms: The smallest unit of an element, composed of protons, neutrons, and electrons.
Elements: Pure substances consisting of only one type of atom, represented on the periodic table.
Compounds: Substances formed from two or more different elements chemically bonded together.

Ionic Bonds: Formed when one atom transfers electrons to another, resulting in oppositely charged ions.
Covalent Bonds: Formed when atoms share electrons.
Metallic Bonds: Bonding that occurs in metals, characterized by a 'sea of electrons' shared among atoms.

Reactants: Substances that undergo a change in a chemical reaction.
Products: Substances formed as a result of a chemical reaction.
Types of Reactions:
- Synthesis: Combining elements to form a compound.
- Decomposition: Breaking down a compound into simpler substances.
- Single Replacement: One element replaces another in a compound.
- Double Replacement: Exchange of components between two compounds.
- Combustion: A reaction involving oxygen that produces energy, typically with hydrocarbons.

Solid: Definite shape and volume, particles closely packed.
Liquid: Definite volume, takes the shape of its container, particles are close but can move.
Gas: No definite shape or volume, particles are far apart and move freely.
Plasma: Ionized gas with free electrons, found in stars.

Groups/Families: Vertical columns; elements with similar properties.
Periods: Horizontal rows; represent energy levels.
Metals, Nonmetals, and Metalloids: Classification based on physical and chemical properties.

Acids: Substances that donate protons (H⁺) in solution, pH < 7.
Bases: Substances that accept protons or produce hydroxide ions (OH⁻), pH > 7.
pH Scale: Measures acidity or alkalinity of a solution, ranging from 0 (acidic) to 14 (basic).

Exothermic Reactions: Release heat, resulting in an increase in temperature.
Endothermic Reactions: Absorb heat, resulting in a decrease in temperature.
Activation Energy: Minimum energy required to initiate a chemical reaction.

Mole: A unit representing 6.022 x 10²³ particles of a substance.
Molar Mass: Mass of one mole of a substance, typically expressed in g/mol.
Balanced Chemical Equations: Represent the conservation of mass in chemical reactions.

Hydrocarbons: Compounds made of hydrogen and carbon; types include alkanes, alkenes, and alkynes.
Functional Groups: Specific groups of atoms within molecules that determine their chemical properties (e.g., -OH for alcohols, -COOH for carboxylic acids).

Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction.
Boyle's Law: For a given mass of gas at constant temperature, pressure and volume are inversely proportional.
Charles's Law: The volume of a gas is directly proportional to its temperature at constant pressure.

Matter refers to anything that possesses mass and occupies space.
Atoms are the fundamental units of elements, made up of protons, neutrons, and electrons.
Elements are pure substances consisting exclusively of one type of atom, identifiable on the periodic table.
Compounds are formed when two or more different elements chemically bond together.

Protons are positively charged particles located in the atomic nucleus.
Neutrons are neutral particles also found in the nucleus, contributing to mass but not charge.
Electrons are negatively charged particles that orbit the nucleus in various energy levels.
The atomic number indicates the number of protons in an atom, defining the element's identity.
The mass number is the combined total of protons and neutrons present in the nucleus.

Ionic bonds occur when one atom transfers electrons to another, generating charged ions that attract each other.
Covalent bonds are formed through the sharing of electrons between atoms, leading to molecular structures.
Metallic bonds exist in metals, characterized by a shared 'sea of electrons' that allows electrical conductivity and malleability.

Reactants are the initial substances that undergo transformation during a chemical reaction.
Products are the new substances created as a result of the chemical reaction.
Types of reactions include:
- Synthesis: Combining multiple elements to create a single compound.
- Decomposition: Breaking down a compound into simpler constituents.
- Single Replacement: An element in a compound is displaced by another element.
- Double Replacement: Components from two compounds exchange partners.
- Combustion: A reaction that consumes oxygen and releases energy, often involving hydrocarbons.

Solids have a fixed shape and volume, with particles tightly packed in a structured arrangement.
Liquids have a definite volume but take the shape of their container, with particles close yet able to move.
Gases have neither fixed shape nor volume, with particles dispersed and moving freely.
Plasma is an ionized state of matter with free-moving electrons, primarily found in stars.

Groups or families are vertical columns representing elements with similar chemical and physical properties.
Periods are horizontal rows that indicate different energy levels among the elements.
Elements are classified into metals, nonmetals, and metalloids based on their traits.

Acids are substances that release protons (H⁺) in solution, having a pH less than 7.
Bases are substances that accept protons or produce hydroxide ions (OH⁻), classified as having a pH greater than 7.
The pH scale quantifies acidity or alkalinity from 0 (highly acidic) to 14 (highly basic).

Exothermic reactions are those that release heat, leading to an increase in the surrounding temperature.
Endothermic reactions absorb heat, resulting in a decrease in temperature.
The activation energy is the minimum energy threshold required to initiate a chemical reaction.

A mole represents 6.022 x 10²³ particles of a substance, serving as a bridge between the macroscopic and atomic scales.
Molar mass refers to the mass of one mole of a substance, commonly expressed in grams per mole (g/mol).
Balanced chemical equations reflect the law of conservation of mass, ensuring the number of atoms remains constant throughout the reaction.

Hydrocarbons are organic compounds primarily composed of hydrogen and carbon, with derivatives known as alkanes, alkenes, and alkynes.
Functional groups are specific clusters of atoms within molecules responsible for defining their chemical behavior (e.g., -OH indicates alcohols, -COOH indicates carboxylic acids).

The Law of Conservation of Mass asserts that mass cannot be created or destroyed during chemical reactions.
Boyle's Law states that for a given mass of gas at constant temperature, pressure is inversely proportional to volume.
Charles's Law establishes that the volume of a gas is directly proportional to its temperature when pressure is held constant.