Key Concepts and Definitions in Chemistry

Posted on Mar 15, 2025 in Chemistry

• Atom: The smallest unit into which matter can be divided by chemical means.
• Specific Heat: The amount of heat required to raise the temperature of one gram of a substance by 1°C.
• Calorie: The amount of heat needed to raise the temperature of one gram of water by 1°C.
• Science: A systematized set of logical knowledge that relates facts to each other.
• Compound: A homogeneous substance resulting from the chemical union of two or more elements; therefore, it may experience further decomposition.
• Liquid Crystals: Materials that lose their rigid organization in only one or two dimensions.
• Element: A simple, elemental substance that cannot be decomposed into simpler ones by ordinary chemical processes.
• Energy: The capacity to perform work.
• Clean Energy: Energy that produces no environmental pollution, such as solar and wind power.
• Physical Phenomenon: A change that a subject undergoes without altering its intimate structure, i.e., without any transformation of substances.
• Chemical Phenomena: A change that produces alterations in the intimate structure of matter and occurs when one or more substances are transformed.
• Fission: The process of dividing a heavy nucleus into particles of approximately equal mass.
• Sources of Power: These may be primary or secondary. Primary sources are where a natural resource is used directly, and secondary sources are obtained by the transformation of primary sources through physical, chemical, or nuclear means.
• Fusion: The opposite of fission; it consists of light atoms joining to form heavier ones.
• Gas: A state of aggregation where the distance between molecules is very large, and intermolecular forces are negligible; it has no definite shape or volume.
• Heterogeneous: You can see its components.
• Homogeneous: We cannot distinguish its components.
• Law of Conservation of Matter: In any reaction, the mass-energy of the reactants is the same as the energy of the products.
• Liquid: A state of aggregation of matter; it has no definite shape, and its volume is fixed.
• Matter: That which constitutes the body, occupies a place in space, and contains mass and energy.
• Amorphous Materials: Substances that have a random, disjointed, and incomplete lattice.
• Scientific Method: The process by which knowledge is achieved, forming a science.
• Mixture: A material resulting from the apparent union of two or more substances.
• Molecule: The smallest portion into which matter can be broken by physical means, retaining the characteristics of the substance.
• Plasma: Ionized gas.
• Chemistry: The science of matter, its intimate structure, its changes, its relations with energy, and the laws that govern these changes and relationships.
• Endothermic: A chemical reaction that absorbs heat.
• Exothermic: A reaction in which heat is evolved.
• Theory: An explanation of an event that is based on many observations and supported by the results of many experiments.
• Substance: Homogeneous material that has a defined and unchanging composition, having the same properties throughout its extension.
• Solid: A state of matter where the molecules are closer together; it presents a definite shape and volume.
• Scientific Molecular Theory: A theory that states that heat and motion are related to the behavior of molecules and explains the properties of the states of matter.
• Solution: A homogeneous mixture that has a variable composition.