Energy and Chemistry of Life Lecture

Vocabulary flashcards covering key terms from the lecture on energy principles, thermodynamics, matter structure, water, acids and bases, chemical reactions, and the role of chemistry in life and the environment.

Energy

The ability to do work.

Work

Occurs when an object is moved over a distance by a force.

Kinetic Energy

Energy possessed by a moving object; depends on mass and velocity.

Potential Energy

Stored energy an object has because of its position; depends on height, distance, and mass.

Mechanical Energy

Energy that sets objects in motion; sum of a system’s kinetic and potential energy.

Chemical Energy

Energy stored in the bonds of molecules and compounds such as food or fossil fuels.

Electrical Energy

Energy resulting from the flow of electric charge; a secondary energy source used for lighting, heating, and powering devices.

Radiant Energy

Energy of electromagnetic waves, including visible light; composed of photons that travel through space.

Thermal (Heat) Energy

Energy that arises from the motion of atoms and molecules when temperature increases.

Nuclear Energy

Energy stored in the nucleus of an atom and released during nuclear reactions; produces little greenhouse gas when used in power plants.

First Law of Thermodynamics

Energy cannot be created or destroyed, only converted from one form to another.

Second Law of Thermodynamics

Whenever energy is converted, some useful energy is lost and entropy increases.

Entropy

The unusable energy in a system; a measure of disorder that increases in energy conversions.

Matter

Anything that has mass and takes up space.

Kinetic Molecular Theory

States that all matter is made of tiny particles in constant motion.

Element

A pure substance made of only one kind of atom and cannot be broken down chemically.

Atom

The smallest unit of an element that retains the properties of that element.

Proton

Positively charged particle located in an atom’s nucleus.

Neutron

Uncharged particle located in an atom’s nucleus.

Electron

Negatively charged particle that orbits the nucleus of an atom.

Molecule

Two or more atoms chemically bonded together.

Ion

An atom or molecule with an electrical charge due to loss or gain of electrons.

Compound

A substance formed when two or more different atoms or ions are chemically bonded, e.g., H₂O, NaCl.

Mixture

A physical combination of atoms, ions, or molecules that are not chemically bonded, e.g., air, concrete.

Water

Universal solvent vital for life; exists naturally as solid, liquid, and gas on Earth.

Hydrogen Ion (H⁺)

A proton released when acids dissolve in water, giving solutions acidic properties.

Acid

Any compound that releases hydrogen ions (H⁺) in solution.

Base

A substance that accepts hydrogen ions, often releasing hydroxide ions (OH⁻).

Hydroxide Ion (OH⁻)

Negatively charged ion that can accept H⁺ to form water; characteristic of bases.

pH Scale

Logarithmic scale (0–14) measuring hydrogen ion concentration; 7 is neutral,

Chemical Bond

Attractive force between atoms due to electron interactions; stores chemical energy.

Exothermic Reaction

Chemical reaction that releases energy because products have lower bond energy than reactants.

Endothermic Reaction

Chemical reaction that absorbs energy because products have higher bond energy than reactants.

Activation Energy

Initial energy input required to start a chemical reaction.

Catalyst

Substance that speeds up a reaction without being consumed or altered, e.g., enzymes.

Enzyme

Protein catalyst that regulates chemical reactions in living organisms at normal temperatures.

Photosynthesis

Process in which plants convert CO₂ and H₂O into sugars using light energy, releasing O₂.

Chlorophyll

Green pigment in chloroplasts that captures sunlight energy for photosynthesis.

Respiration

Process of breaking down organic molecules with oxygen to release usable energy, producing CO₂ and H₂O.

Inorganic Matter

Small molecules or ion combinations that usually lack carbon; examples include water, salt, metals.

Organic Matter

Carbon-containing molecules often arranged in chains or rings; includes sugars, proteins, fats.

Persistent Organic Chemical

Organic compound resistant to microbial breakdown, lingering in the environment and causing pollution.