OAE Integrated Science key terms

A testable, falsifiable statement proposing a possible explanation for an observation, framed so that evidence could support or contradict it. It guides what data to collect next.

An investigation in which only one factor is deliberately changed while all other conditions are held constant, so any measured difference can be attributed to that factor rather than to chance or confounds.

The factor a researcher deliberately manipulates or selects across treatment levels in an experiment. It is the presumed cause, plotted on the horizontal axis of a graph.

The factor that is measured or observed as a response in an experiment. Its value is expected to change when the independent variable changes, and it is plotted on the vertical axis.

The comparison condition in an experiment that receives no treatment or a neutral treatment, providing a baseline against which the effects of the experimental treatment can be judged.

A broad, well-supported explanation for a body of evidence that has survived repeated testing and makes further predictions. It is stronger than a hypothesis, not a mere guess.

A concise statement, often mathematical, describing a consistent regularity observed in nature, such as conservation of mass. It describes what happens, while a theory explains why.

Evaluation of a study's methods, analysis, and conclusions by independent experts before publication. It filters obvious errors and bias but does not guarantee that findings are correct.

A systematic error that pushes measurements or conclusions consistently in one direction, arising from flawed sampling, faulty instruments, or the expectations of researchers or subjects.

An inert or sham treatment given to a comparison group so that participants cannot tell whether they received the active treatment, helping separate real effects from expectation.

Accuracy is how close a measurement is to the true value; precision is how closely repeated measurements agree with one another. A result can be precise yet inaccurate if a systematic error is present.

The digits in a measured value that carry meaningful information about its precision, including all certain digits plus one estimated digit. Rules govern how they are handled in calculations.

A compact way to write very large or very small numbers as a coefficient between 1 and 10 multiplied by a power of ten, such as 3.2 x 10^4 for 32,000.

The mass of a substance per unit volume, usually expressed in grams per cubic centimeter or kilograms per cubic meter. It explains floating and sinking and identifies pure substances.

Mass is the amount of matter in an object, unchanged by location. Weight is the gravitational force on that mass and varies with the local strength of gravity.

The amount of three-dimensional space an object or sample occupies, commonly measured in liters, milliliters, or cubic centimeters, and often found by displacement for irregular solids.

Three principles: objects resist changes in motion unless a net force acts; acceleration equals net force divided by mass; and every action has an equal and opposite reaction.

A push or pull that can change an object's speed, direction, or shape, measured in newtons. Forces combine as vectors, so direction matters as much as magnitude.

Work is done when a force moves an object through a distance in the direction of the force. Energy is the capacity to do work and is measured in joules.

The principle that energy cannot be created or destroyed, only transferred between objects or transformed among forms such as kinetic, potential, thermal, and chemical energy.

Movement of thermal energy by conduction through direct contact, convection through fluid currents, or radiation through electromagnetic waves. Net flow is always from hotter to cooler objects.

Temperature measures the average kinetic energy of particles in a sample. Thermal energy is the total kinetic energy of all those particles, so it also depends on amount of matter.

The smallest unit of an element that retains that element's chemical properties, consisting of a nucleus of protons and neutrons surrounded by electrons in energy levels.

A pure substance made of only one kind of atom, defined by its atomic number, the count of protons in the nucleus. Elements cannot be broken down by ordinary chemical means.

An arrangement of elements in order of increasing atomic number, organized into groups with similar properties and periods. Position predicts reactivity, atomic size, and bonding behavior.

A compound is a substance formed when elements bond in fixed proportions and can be broken down chemically. A mixture combines substances in variable proportions that keep their own properties.

An attractive force holding atoms together, formed by transferring electrons (ionic), sharing electrons (covalent), or delocalized electrons among metal atoms (metallic).

A process in which bonds break and form, rearranging atoms into new substances. Mass is conserved, and the reaction may absorb or release energy.

The principle that the total mass of the substances involved in a chemical reaction stays the same because atoms are neither created nor destroyed, only rearranged.

A symbolic representation of a chemical reaction in which coefficients make the number of atoms of each element equal on both sides, reflecting conservation of mass.

An acid donates hydrogen ions and has a pH below 7; a base accepts hydrogen ions and has a pH above 7. They neutralize each other to form water and a salt.

A logarithmic scale from 0 to 14 expressing hydrogen ion concentration. Each whole step represents a tenfold change in acidity, so pH 4 is ten times more acidic than pH 5.

The principle that all living things are made of one or more cells, the cell is the basic unit of life, and new cells arise only from existing cells.

Prokaryotes are cells lacking a membrane-bound nucleus, such as bacteria. Eukaryotes have a nucleus and organelles, and include protists, fungi, plants, and animals.

A specialized structure inside a eukaryotic cell that performs a particular function, such as mitochondria for energy release, ribosomes for protein building, or chloroplasts for photosynthesis.

Photosynthesis uses light energy to convert carbon dioxide and water into glucose and oxygen. Cellular respiration releases energy from glucose, using oxygen and producing carbon dioxide and water.

Mitosis divides one cell into two genetically identical cells for growth and repair. Meiosis produces gametes with half the chromosome number, creating genetic variation.

The passing of traits from parents to offspring through genes carried on chromosomes, following patterns such as dominance, segregation, and independent assortment described by Mendel.

Genotype is the combination of alleles an organism carries for a trait. Phenotype is the observable characteristic that results from that genotype interacting with the environment.

The process by which individuals with inherited traits better suited to their environment tend to survive and reproduce more, shifting the traits of a population over generations.

An inherited feature or behavior that improves an organism's ability to survive and reproduce in a particular environment, arising over generations through natural selection.

A sequence showing how energy passes from producers to consumers as one organism eats another. Arrows point in the direction energy flows, and only about ten percent transfers to the next level.

A community of interacting organisms plus the nonliving factors of their environment, such as water, soil, and sunlight, connected by flows of energy and cycling of matter.

The maximum population size an environment can sustain indefinitely given available food, water, space, and other limiting resources, often shown as the plateau of a growth curve.

The ongoing transformation of rock among igneous, sedimentary, and metamorphic types through melting, cooling, weathering, erosion, compaction, and heat and pressure.

The theory that Earth's rigid outer shell is broken into plates that move over the mantle, causing earthquakes, volcanoes, mountain building, and seafloor spreading at their boundaries.

Weathering breaks rock into smaller pieces in place by physical or chemical means. Erosion transports the resulting sediment away by water, wind, ice, or gravity.

The laying down of eroded sediment when transporting agents lose energy, building layers that may later compact and cement into sedimentary rock.

An earthquake is ground shaking released when stressed rock ruptures along a fault. A volcano is an opening where magma reaches the surface, both concentrated near plate boundaries.

The continuous circulation of water among oceans, atmosphere, and land through evaporation, transpiration, condensation, precipitation, runoff, and infiltration, driven mainly by solar energy.

Weather is the short-term state of the atmosphere at a place and time. Climate is the long-term average pattern of weather, typically assessed over thirty years or more.

The interacting motions of Earth, the Sun, and the Moon that produce day and night, seasons, moon phases, eclipses, and tides. Seasons result from Earth's axial tilt, not distance from the Sun.

The Sun and all objects gravitationally bound to it, including eight planets, dwarf planets, moons, asteroids, and comets, formed from a rotating cloud of gas and dust.

The attractive force between any objects with mass, increasing with mass and decreasing with the square of distance. It governs orbits and formed the planets from debris.