Learn Chemistry

Aromaticity, resonance stabilization, ring strain, and carbocation stability. These determine which molecules persist and which decompose. You will encounter this when predicting whether a compound will survive reaction conditions or fall apart.

pKa values, conjugate base stability, and the factors that make a proton easy or hard to remove. Electronegativity, resonance, induction, and atom size all play a role. Essential for understanding buffer systems and organic reaction mechanisms.

Single, double, and triple bond energies and what makes one bond stronger than another. Bond length, orbital overlap, and electronegativity differences matter. This determines reaction enthalpies and which bonds break first.

The tendency of an atom to attract shared electrons. Trends across the periodic table, Pauling scale values, and how electronegativity differences create polar bonds and influence molecular properties.

How atomic properties change across periods and down groups. Electronegativity, atomic radius, ionization energy, and electron affinity follow predictable patterns that explain chemical reactivity.

How electrons fill orbitals according to the Aufbau principle, Hund's rule, and the Pauli exclusion principle. Includes common exceptions like chromium and copper where half-filled or filled d-subshells are favored.

Thermodynamic and kinetic factors that determine whether a reaction proceeds. Gibbs free energy, enthalpy, entropy, activation energy, and Le Chatelier's principle. Predicting which direction a reaction will go under given conditions.

Like dissolves like, solubility rules for ionic compounds, and the role of intermolecular forces. Hydrogen bonding, polarity, and lattice energy determine whether a substance dissolves in water or organic solvents.

Electron transfer reactions, standard reduction potentials, and the activity series. Identifying oxidizing and reducing agents, balancing redox equations, and predicting spontaneous reactions in electrochemistry.

Reactivity patterns of alcohols, aldehydes, ketones, carboxylic acids, amines, and esters. How functional group identity determines chemical behavior, acidity, basicity, and reaction pathways in organic chemistry.

Reaction coordinate diagrams showing activation energy, transition states, and intermediates. Covers exothermic vs endothermic profiles, the effect of catalysts, and how energy barriers determine reaction rates.

How molecules are drawn and what those drawings communicate. Covers skeletal structures, resonance notation, constitutional isomers, and the difference between open-chain and cyclic forms of the same compound.

Three-dimensional shapes of molecules predicted by VSEPR theory. Covers bond angles, lone pair repulsion, and why water is bent, methane is tetrahedral, and ammonia is pyramidal.

Spatial arrangement of atoms in molecules and how it affects properties. Covers Newman projections, Fischer projections, chair conformations, and the difference between cis/trans and R/S configurations.

Visualization of electron density and charge distribution in molecules. Covers polar vs nonpolar bonds, net dipole moments, and the spectrum from ionic to covalent bonding character.

How amino acid chains fold into functional shapes. Covers alpha helices, beta sheets, primary through quaternary structure levels, and the forces that stabilize each level. Understanding protein architecture is essential for biochemistry and drug design.