BSSE General Science 1430 key terms

A testable, tentative explanation for a specific observation or question that can be supported or refuted by further evidence.

A well-substantiated explanation of some aspect of the natural world that is based on a body of evidence and has survived repeated testing.

An investigation in which all variables except the one being tested are kept constant, allowing a cause-and-effect relationship to be identified.

The factor that a researcher deliberately changes or manipulates in an experiment to observe its effect on another variable.

The factor that is measured or observed in an experiment; its value is expected to change in response to the independent variable.

A way of writing very large or very small numbers as a coefficient between 1 and 10 multiplied by a power of ten, such as 3.2 × 10^4.

The digits in a measurement that carry meaningful information about its precision, including all certain digits and one estimated digit.

Precision refers to how close repeated measurements are to each other; accuracy refers to how close a measurement is to the true value.

The internationally agreed system of measurement units, including the meter for length, kilogram for mass, second for time, and kelvin for temperature.

The mass of a substance per unit volume, often expressed in grams per cubic centimeter or kilograms per cubic meter.

The smallest unit of an element that retains the chemical properties of that element, consisting of a nucleus and orbiting electrons.

A pure substance made of only one kind of atom, defined by its atomic number and listed on the periodic table.

A substance formed when two or more different elements are chemically bonded together in fixed proportions.

The smallest particle of a covalent compound or element that consists of two or more atoms bonded together.

A process in which substances are transformed into new substances with different properties by breaking and forming chemical bonds.

The principle that matter is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

A push or pull that can change an object's motion, direction, or shape, measured in newtons.

Three principles describing how forces affect motion: inertia, the relationship between force, mass, and acceleration, and action-reaction pairs.

The rate at which an object's velocity changes with time, including changes in speed, direction, or both.

The energy an object possesses due to its motion, calculated as one-half the mass times the square of its speed.

Stored energy that an object has because of its position or condition, such as gravitational potential energy due to height.

The principle that energy cannot be created or destroyed but can only change from one form to another.

A disturbance that transfers energy through space or a medium without transferring matter, characterized by wavelength, frequency, and amplitude.

The rate at which electric charge flows through a conductor, measured in amperes.

The electric potential difference between two points in a circuit, which drives current flow and is measured in volts.

The opposition to the flow of electric current in a material, measured in ohms; it depends on the material's properties and dimensions.

The range of all types of electromagnetic radiation, from radio waves to gamma rays, ordered by wavelength and frequency.

The theory that Earth's lithosphere is divided into rigid plates that move over the asthenosphere, causing earthquakes, volcanoes, and mountain building.

A sudden shaking of the ground caused by the release of energy when rocks along a fault break and slip.

A fracture in Earth's crust along which rocks on either side have moved relative to each other.

The continuous processes by which igneous, sedimentary, and metamorphic rocks are formed, broken down, and transformed over time.

Weathering is the breakdown of rocks by physical or chemical processes; erosion is the transport of the resulting sediments by water, wind, or ice.

The warming of Earth's surface caused by atmospheric gases trapping outgoing infrared radiation, keeping the planet habitable.

Long-term shifts in global or regional climate patterns, including temperature and precipitation, often driven by human activities.

The Sun and all the celestial bodies bound to it by gravity, including planets, moons, asteroids, and comets.

A large, nearly spherical body that orbits a star, has cleared its orbital neighborhood, and does not produce its own light.

The smallest structural and functional unit of life, capable of performing essential life processes.

Deoxyribonucleic acid, the molecule that carries genetic instructions for the development and functioning of living organisms.

A segment of DNA that contains the instructions for making a protein or functional RNA, and is the basic unit of heredity.

A change in the DNA sequence that can alter gene function and is a source of genetic variation.

The process by which individuals with traits better suited to their environment tend to survive and reproduce, increasing the frequency of those traits.

The change in the genetic composition of populations over generations, leading to the diversity of life.

The ability of an organism to maintain stable internal conditions, such as temperature and pH, despite changes in the external environment.

A community of living organisms interacting with each other and their nonliving environment in a defined area.

A network of interconnected food chains showing the feeding relationships and energy flow among organisms in an ecosystem.

The variety of life in a particular habitat or on Earth as a whole, including genetic, species, and ecosystem diversity.