Chemistry is the science of matter and the changes it undergoes. Everything around us is made of atoms and molecules, and chemistry helps us understand how they interact.
Key Concepts in Chemistry:
Atoms - The building blocks of all matter
Elements - Pure substances made of one type of atom
Compounds - Substances made of different atoms bonded together
Chemical Reactions - Processes where atoms rearrange to form new substances
Chemical Bonds - Forces that hold atoms together
Chemistry in Daily Life:
🍳 Cooking: Heat causes chemical reactions that change food's taste and texture
🔋 Batteries: Chemical reactions produce electrical energy
🌱 Photosynthesis: Plants convert CO₂ and water into glucose using sunlight
💊 Medicine: Drugs are molecules designed to interact with specific parts of our body
🧼 Soap: Molecules with both water-loving and oil-loving parts clean by surrounding dirt
Your Chemistry Journey
Lessons Completed: 0/5
Molecules Built: 0
Accuracy: 0%
Atomic Structure
Atoms are the smallest units of elements. They consist of a nucleus (protons and neutrons) surrounded by electrons.
Parts of an Atom:
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
Mass Number = Protons + Neutrons
Build an Atom
Current atom: 0 protons, 0 neutrons, 0 electrons
If carbon has 6 protons and 6 neutrons, what is its mass number?
The Periodic Table
The periodic table organizes all known elements by their atomic number. Elements in the same column have similar properties.
Periodic Table Organization:
Periods: Horizontal rows
Groups: Vertical columns
Metals: Left side, good conductors
Nonmetals: Right side, poor conductors
Metalloids: In between, semiconductor properties
Interactive Periodic Table (First 20 Elements)
Selected Element: None
What is the symbol for Oxygen?
Molecules and Chemical Bonds
Molecules form when atoms bond together. The type of bond depends on how electrons are shared or transferred.
Types of Chemical Bonds:
Covalent Bonds: Atoms share electrons (H₂O, CO₂)
Ionic Bonds: Electrons transfer from one atom to another (NaCl, CaF₂)
Metallic Bonds: Electrons form a "sea" around metal atoms
H₂O = 2 Hydrogen + 1 Oxygen
CO₂ = 1 Carbon + 2 Oxygen
Molecule Visualizer
Current molecule: None selected
How many atoms are in one molecule of methane (CH₄)?
Chemical Reactions
Chemical reactions rearrange atoms to form new substances. The total number of atoms is conserved.
Types of Reactions:
Synthesis: A + B → AB
Decomposition: AB → A + B
Single Replacement: A + BC → AC + B
Double Replacement: AB + CD → AD + CB
Combustion: Fuel + O₂ → CO₂ + H₂O
2H₂ + O₂ → 2H₂O (Hydrogen + Oxygen → Water)
Reaction Simulator
In the reaction 2H₂ + O₂ → 2H₂O, how many water molecules are produced?
🎯 Chemistry Practice Test
Test your chemistry knowledge with problems covering all topics!