Chemical Bonds & Reactions

Electron

A subatomic particle with a negative charge that orbits the nucleus of an atom, playing a key role in chemical reactions.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in forming bonds with other atoms.

Electronegativity

A measure of an atom's ability to attract and hold onto electrons when forming a chemical bond.

Octet Rule

A chemical rule of thumb that states atoms tend to bond in such a way that they have eight electrons in their valence shell, achieving a stable electron configuration.

Electron Shells

Regions around nucleus holding electrons and energy.

Valence Electron Shell

Outermost shell involved in chemical bonding.

Ionic Bonds

Complete transfer of electrons between atoms.

Ions

Atoms that have gained or lost electrons.

Anion

Negatively charged ion from electron gain.

Cation

Positively charged ion from electron loss.

Covalent Bonds

Sharing of valence electrons between atoms.

Polar Bonds

Unequal electron sharing causing partial charges.

Nonpolar Bonds

Equal electron sharing resulting in balanced charge.

Hydrogen Bonds

Attractions between partially charged atoms.

Solubility in water

Determined by polarity; polar molecules dissolve well.

Chemical Reaction

Process where reactants transform into products.

Reactants

Substances that enter a reaction.

Products

Substances formed as a result of a reaction.

Synthesis Reaction

Combines reactants to form larger, complex molecules.

Decomposition Reaction

Breaks down a molecule into simpler components.

Exchange Reaction

Involves both synthesis and decomposition processes AB + C --> AC + B

Redox Reaction

Involves electron transfer; oxidation and reduction.

Oxidation

Loss of electrons during a chemical reaction.

Reduction

Gain of electrons during a chemical reaction.

Exergonic reactions

release energy

Endergonic reactions

absorb energy

Chemical Equilibrium

A state in a reversible chemical reaction where the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products.

Temperature

Higher temperature increases the reaction rate

Concentration

Higher concentration increases the reaction rate

Particle Size

Smaller particles increases the reaction rate

Catalyst

A substance that increases the rate of a chemical reaction without being used (enzymes)