⚗️ Chemistry Essentials

What you’ll learn

1. Atomic Structure and IsotopesDescribe the parts of an atom, use atomic and mass numbers, explain isotopes, and identify valence electrons and electron shells.Atoms have a nucleus of protons and neutrons surrounded by electrons. The atomic number (protons) defines the element; the mass number adds neutrons. Isotopes are atoms of one element with different neutron counts. Electrons fill shells, and the outer valence electrons, seeking a full shell, drive all chemical bonding.
2. The Periodic Table and TrendsExplain how the periodic table is organized, distinguish metals, nonmetals, and metalloids, and describe key periodic trends.The periodic table orders elements by atomic number into periods and groups, with shared group behavior from matching valence electrons. Elements sort into metals, nonmetals, and metalloids. Trends are predictable: atomic size and electronegativity change across periods and down groups, letting you compare elements from their position alone.
3. Chemical BondingExplain why atoms bond and distinguish ionic, covalent, and metallic bonds and the properties each produces.Atoms bond to reach stable, full outer shells. Ionic bonds transfer electrons between a metal and nonmetal, forming charged crystals like salt. Covalent bonds share electrons between nonmetals, forming molecules like water. Metallic bonds pool electrons into a mobile sea, giving metals their conductivity and malleability.
4. Reactions and Balancing EquationsDefine chemical reactions, write and balance equations, and recognize the main types of reactions.In a reaction, reactants become products as bonds rearrange, with atoms conserved. Chemists write equations with formulas and an arrow, then balance them using coefficients so each atom tallies on both sides. Reaction types include synthesis, decomposition, replacement, and combustion, and reactions can release or absorb energy.
5. The Mole and StoichiometryExplain the mole and Avogadro's number, use molar mass, and apply stoichiometry to relate amounts in a reaction.The mole is a counting unit equal to Avogadro's number, about 6.02 x 10 to the 23 particles, letting chemists weigh a known number of atoms. Molar mass in grams equals the atomic or molecular mass. Stoichiometry uses the mole ratios in a balanced equation to calculate how much reactant is needed and product formed.
6. Acids and BasesDefine acids and bases, read the pH scale, and explain neutralization reactions and their uses.Acids release hydrogen ions and taste sour; bases release hydroxide ions and feel slippery. The pH scale from 0 to 14 measures acidity, with 7 neutral, and it is logarithmic. When acids and bases mix, they neutralize to produce water and a salt, a reaction used in antacids, agriculture, and titration.
7. Organic Chemistry PreviewExplain why carbon is central to organic chemistry, how organic molecules are built, and why the field matters.Organic chemistry studies carbon compounds. Carbon forms four bonds and links into chains, rings, and branches, creating millions of molecules. Organic molecules are organized by functional groups that give characteristic properties. From hydrocarbons to proteins, organic chemistry underlies biology, medicine, fuels, and materials.

Questions this course answers

Grounded in trusted sources

• Royal Society of Chemistry
• Encyclopaedia Britannica
• Khan Academy Chemistry
• National Institute of Standards and Technology

Every Wunder lesson is built from real, reputable sources — never invented.

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