Basic Concepts of Chemistry Quiz

Matter: Anything that has mass and occupies space; exists in solid, liquid, or gas states.
Atoms: Basic units of matter; consist of protons, neutrons, and electrons.
Elements: Pure substances made up of only one type of atom; represented by symbols (e.g., H for hydrogen).
Compounds: Substances formed from two or more elements chemically bonded together (e.g., H2O).
Mixtures: Combinations of two or more substances that retain their individual properties (e.g., air, salad).

Arranged by Atomic Number: Elements are organized by the number of protons.
Groups/Families: Vertical columns; elements share similar chemical properties (e.g., Group 1: Alkali Metals).
Periods: Horizontal rows; indicate the number of electron shells.

Ionic Bonds: Formed through the transfer of electrons from one atom to another; creates charged ions (e.g., NaCl).
Covalent Bonds: Formed by sharing electrons between atoms (e.g., O2).
Metallic Bonds: Bonding due to the attraction between positively charged metal ions and delocalized electrons.

Reactants: Substances that undergo change during a reaction.
Products: New substances formed as a result of the reaction.
Types of Reactions:
1. Synthesis: A + B → AB
2. Decomposition: AB → A + B
3. Single Replacement: A + BC → AC + B
4. Double Replacement: AB + CD → AD + CB
5. Combustion: Hydrocarbon + O2 → CO2 + H2O

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

Acids: Substances that donate protons (H+ ions); taste sour; turn blue litmus paper red (e.g., HCl).
Bases: Substances that accept protons; feel slippery; turn red litmus paper blue (e.g., NaOH).
pH Scale: Measures acidity or alkalinity; ranges from 0 (acidic) to 14 (basic), with 7 being neutral.

Mole: Unit measuring the amount of substance; 1 mole = 6.022 x 10^23 particles (Avogadro's number).
Stoichiometry: Calculation of reactants and products in chemical reactions based on the balanced equation.

Exothermic Reactions: Release heat; products have lower energy than reactants.
Endothermic Reactions: Absorb heat; products have higher energy than reactants.
Enthalpy (H): Total heat content of a system; changes during reactions are measured as ΔH.

Boyle's Law: Pressure inversely relates to volume (P1V1 = P2V2) at constant temperature.
Charles's Law: Volume directly relates to temperature (V1/T1 = V2/T2) at constant pressure.
Ideal Gas Law: PV = nRT; relates pressure (P), volume (V), number of moles (n), gas constant (R), and temperature (T).

Solvent: Substance that dissolves a solute, usually present in greater amount (e.g., water).
Solute: Substance dissolved in a solvent (e.g., salt in water).
Concentration: Amount of solute in a given volume of solution; can be expressed in molarity (M), mass/volume percent, etc.

Matter exists in three states: solid, liquid, and gas.
Atoms are the building blocks of matter and are made up of protons, neutrons, and electrons.
Elements are pure substances made up of only one type of atom and are represented by symbols (like H for hydrogen).
Compounds are formed when two or more elements chemically bond together (like H₂O).
Mixtures are combinations of different substances that retain their individual properties (like air or salad).

Elements are organized on the Periodic Table by their atomic number (number of protons).
Groups/Families are vertical columns and elements within a group share similar chemical properties.
Periods are horizontal rows and indicate the number of electron shells in an atom.

Ionic Bonds form when one atom transfers electrons to another, creating charged ions.
Covalent Bonds form when atoms share electrons.
Metallic Bonds occur in metals due to the attraction between positively charged metal ions and delocalized electrons.

Reactants are the starting materials in a chemical reaction.
Products are the new substances formed as a result of a reaction.
Types of Reactions:
- Synthesis: A + B → AB
- Decomposition: AB → A + B
- Single Replacement: A + BC → AC + B
- Double Replacement: AB + CD → AD + CB
- Combustion: Hydrocarbon + O₂ → CO₂ + H₂O

Solids have a definite shape and volume because their particles are tightly packed.
Liquids have a definite volume but take the shape of their container because their particles are less tightly packed than in solids.
Gases have no fixed shape or volume because their particles are far apart and move freely.

Acids donate protons (H⁺ ions), taste sour, and turn blue litmus paper red.
Bases accept protons, feel slippery, and turn red litmus paper blue.
The pH scale measures acidity and alkalinity, ranging from 0 (acidic) to 14 (basic), with 7 being neutral.

A mole is a unit of substance equal to 6.022 x 10²³ particles (Avogadro's number).
Stoichiometry is the calculation of quantities of reactants and products in chemical reactions, based on the balanced chemical equation.

Exothermic reactions release heat, meaning the products have lower energy than the reactants.
Endothermic reactions absorb heat, meaning the products have higher energy than the reactants.
Enthalpy (H) represents the total heat content of a system. Changes in enthalpy (ΔH) are measured during reactions.

Boyle's Law states that pressure and volume are inversely related at constant temperature (P₁V₁ = P₂V₂).
Charles's Law states that volume and temperature are directly related at constant pressure (V₁/T₁ = V₂/T₂).
The Ideal Gas Law describes the relationship between pressure (P), volume (V), number of moles (n), gas constant (R), and temperature (T): PV = nRT.

A solvent dissolves a solute, usually present in a greater amount (e.g., water).
Concentration measures the amount of solute in a given volume of solution. It can be expressed in various units such as molarity (M), mass/volume percent, etc.