Chemistry

Chemical formulas and structural models describe the atoms in a substance and how they are arranged. These foundations connect the identity of elements to the structures and properties of molecules.

• Chemistry 2e: Chapter 2 Summary

  Review atomic structure, chemical formulas, the periodic table, and ionic and molecular compounds.

Atom

The smallest particle of an element that retains that element’s identity in chemical combinations.

Isotope

An atom of an element with the same atomic number as other atoms of that element but a different mass number.

A balanced equation shows the reactants and products, while a reaction mechanism describes the sequence of steps by which a reaction occurs. Studying reactions links chemical formulas to changes in bonding and to measurable rates.

• Chemistry 2e: 12.5 Collision Theory

  Use this section to connect collisions, orientation, and energy with reaction rates.

Reaction mechanism

A step-by-step description of how a chemical reaction occurs.

Intermediate

A species formed in one reaction step and consumed in a later step.

Thermodynamics and chemical equilibrium describe how energy and conditions relate to chemical systems. Kinetics focuses on reaction rates, which collision theory connects to the frequency, orientation, and energy of molecular collisions.

• Chemistry 2e: 12.5 Collision Theory

  This section describes how collision energy and orientation affect whether reactants form products.

Activation energy

The minimum energy needed for reactants to form products during a collision.

Redox reaction

A reaction involving changes in oxidation states; some redox reactions transfer electrons between reactant species.

Organic chemistry examines carbon-containing compounds, including hydrocarbons whose carbon atoms can form chains and rings. Biochemistry applies chemical ideas to living systems, including biological macromolecules and the reactions that build or break them down.

• Biological Chemistry I

  The course explores cell chemistry, protein structures, catalysis, and metabolism.

Hydrocarbon

An organic compound containing only carbon and hydrogen.

Monomer

A molecular subunit that can combine with other subunits to form a larger molecule such as a polymer.