NGSA Science flashcards
NGSA Science · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Newton's Second Law
- The acceleration of an object equals the net force on it divided by its mass (a = F/m). Acceleration points in the direction of the net force.
- Conservation of Energy
- Energy cannot be created or destroyed, only transferred or transformed. In a closed system the total energy stays constant, though some may become less useful.
- Wave Speed Equation
- Wave speed equals frequency multiplied by wavelength (v = fλ). In a given medium, changing frequency changes wavelength inversely if speed is constant.
- Ohm's Law
- Voltage equals current times resistance (V = IR). For a fixed resistance, increasing voltage increases current; increasing resistance decreases current.
- Series vs. Parallel
- In series circuits, current is the same through each component and resistances add. In parallel, voltage is equal across branches and currents add.
- Density and Floating
- Density equals mass divided by volume. An object floats in a fluid when its average density is less than the fluid's density and sinks when greater.
- Acids and Bases
- Acids donate hydrogen ions in water and have pH below 7; bases accept hydrogen ions and have pH above 7. Neutralization forms water and a salt.
- Cell Theory
- All living organisms are made of one or more cells, the cell is the basic unit of life, and new cells arise from existing cells.
- Prokaryote vs. Eukaryote
- Prokaryotic cells lack a membrane-bound nucleus and organelles; eukaryotic cells have a nucleus and membrane-bound organelles such as mitochondria and chloroplasts.
- Photosynthesis
- Chloroplasts use light energy to convert carbon dioxide and water into glucose and oxygen. The glucose stores chemical energy used by the organism.
- Cellular Respiration
- Mitochondria break down glucose using oxygen to release carbon dioxide, water, and usable ATP energy. It is essentially the reverse of photosynthesis.
- DNA Base Pairing
- In the DNA double helix, adenine pairs with thymine and cytosine pairs with guanine. Each strand serves as a template during replication.
- Natural Selection
- Heritable variations that improve survival and reproduction become more common in a population over generations because those individuals leave more offspring.
- Negative Feedback
- A control mechanism in which a deviation from a set point triggers a response that reduces the deviation, helping maintain homeostasis in living systems.
- Genotype and Phenotype
- Genotype is the combination of alleles an organism carries; phenotype is the observable trait produced by that genotype interacting with the environment.
- Earth's Layers
- From outside inward, Earth consists of the crust, mantle, liquid outer core, and solid inner core. Motion in the outer core generates the magnetic field.
- Plate Boundaries
- Divergent boundaries create new crust, convergent boundaries cause subduction or mountain building, and transform boundaries produce lateral sliding and earthquakes.
- Rock Types
- Igneous rock forms from cooling magma or lava, sedimentary rock from compacted sediments, and metamorphic rock from heat and pressure on existing rock.
- Law of Superposition
- In undisturbed rock layers, older layers lie below younger ones. This principle lets geologists establish the relative ages of rock sequences.
- Water Cycle
- Solar energy drives evaporation and transpiration, condensation forms clouds, precipitation returns water, and infiltration and runoff move it across land.
- Cause of Seasons
- Earth's axis is tilted about 23.5 degrees, so each hemisphere receives more direct sunlight and longer days for part of the year.
- Moon Phases
- Phases result from the changing angle between Earth, the Moon, and the Sun as the Moon orbits. Solar eclipses occur at new moon; lunar eclipses at full moon.
- Hertzsprung–Russell Diagram
- A graph plotting star luminosity against temperature. It organizes stars into main sequence, giants, supergiants, and white dwarfs, revealing stellar evolution patterns.
- Engineering Design Cycle
- A repeating process: define the problem, research constraints, generate solutions, prototype, test and evaluate, then revise. Iteration improves the design.
- Criteria and Constraints
- Criteria are the goals a design must achieve; constraints are the limits such as budget, materials, time, and safety within which it must work.
- Trade-offs in Design
- Improving one design criterion often worsens another. Engineers compare options against multiple criteria and constraints to find the best overall solution.
- Role of Prototypes
- A prototype is a simplified working model used to test design ideas. Its usefulness depends on how well it represents the important features of the final product.
- Systems and Feedback
- A system has inputs, processes, outputs, and boundaries. Feedback loops return information that can stabilize the system or drive it to change.
- Accuracy vs. Precision
- Accuracy is how close a measurement is to the true value; precision is how close repeated measurements are to each other. They are independent qualities.
- Patterns as a Concept
- Observed regularities can be used to classify objects, predict future events, and explain phenomena across physical, life, and Earth sciences.
- Controlled Experiment
- A test that changes one independent variable while holding other conditions constant, measuring a dependent variable and comparing against a control group.
- Structure and Function
- The shape, arrangement, and properties of an object or system's parts determine what it can do and how it behaves.
- Stability and Change
- Systems can stay stable through feedback or change when forces and inputs shift. Scientists quantify the rate and direction of such changes.