OST Grade 5 Science flashcards
OST Grade 5 Science · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Rotation
- The spinning of Earth on its axis, which takes about 24 hours. This motion causes day and night and makes the Sun appear to move across the sky.
- Revolution
- The movement of Earth around the Sun in an orbit that takes about 365.25 days. Combined with Earth's tilted axis, it causes the yearly cycle of seasons.
- Moon phases
- The changing shapes of the lit part of the Moon we see from Earth. They repeat about every 29.5 days, from new moon through full moon and back.
- Solar eclipse
- An event during a new moon when the Moon passes between Earth and the Sun and blocks sunlight. Only places in the Moon's shadow see the eclipse.
- Law of superposition
- A rule that in undisturbed rock layers, the oldest layer is at the bottom and the youngest is at the top. Fossils in layers show their relative ages.
- Erosion
- The carrying away of weathered rock and soil by water, wind, ice, or gravity. Erosion moves material from one place and deposition drops it somewhere else.
- Water cycle
- The continuous movement of water through evaporation, condensation, precipitation, and collection. The Sun provides the energy that drives evaporation from oceans and lakes.
- Producer
- An organism, such as a plant or algae, that makes its own food using sunlight through photosynthesis. Producers form the base of every food chain.
- Decomposer
- An organism such as a fungus or bacterium that breaks down dead plants and animals. Decomposers return nutrients to the soil so producers can use them.
- Photosynthesis
- The process in which green plants use sunlight, carbon dioxide, and water to make sugar and release oxygen. Chloroplasts in leaves carry out this process.
- Adaptation
- An inherited trait that helps an organism survive in its habitat, such as camouflage, thick fur, or a long beak. Adaptations develop over many generations.
- Inherited trait
- A characteristic passed from parents to offspring through genes, such as eye color or fur pattern. Inherited traits are present from birth.
- Learned behavior
- A behavior an animal acquires through experience or observation, such as riding a bike or a bird learning a song. It is not passed through genes.
- Natural selection
- The process in which organisms with helpful variations survive and reproduce more often. Over generations those helpful traits become more common in the population.
- Food web
- A model of overlapping food chains that shows how energy passes among producers, consumers, and decomposers. It shows that most organisms eat more than one kind of food.
- Symbiosis
- A close long-term relationship between two different species. Mutualism helps both, commensalism helps one only, and parasitism helps one while harming the other.
- Physical change
- A change in the form of matter without making a new substance, such as melting ice or dissolving sugar. The material keeps its identity and can often be reversed.
- Chemical change
- A change that produces a new substance with different properties. Signs include color change, gas bubbles, heat or light, or a new smell, as in rusting.
- Density
- The amount of mass in a given volume, calculated as mass divided by volume. An object floats in water if its density is less than water's density.
- Mixture
- Two or more substances combined without a chemical reaction, so each keeps its properties. Mixtures, like sand and iron filings, can be separated by physical methods.
- Balanced forces
- Equal forces acting on an object in opposite directions. Balanced forces do not change the object's motion, so it stays still or keeps moving at a steady speed.
- Unbalanced forces
- Forces that do not cancel out, leaving a net force in one direction. Unbalanced forces change an object's speed or direction of motion.
- Inertia
- The tendency of an object to resist a change in motion. An object at rest stays at rest and a moving object keeps moving unless a force acts on it.
- Energy transformation
- A change of energy from one form to another, such as electrical energy becoming light and heat in a bulb. Energy is never created or destroyed.
- Conduction
- The transfer of heat through direct contact between materials, as when a metal spoon gets hot in soup. Materials that move heat easily are conductors.
- Series circuit
- A circuit with only one path for current to follow. If one bulb or wire breaks, the whole circuit stops working, and all bulbs go out.
- Independent variable
- The one factor an experimenter changes on purpose in an investigation. It is the 'cause' side of a fair test, such as the amount of water given to plants.
- Dependent variable
- The factor an experimenter measures or observes as a result. It responds to the independent variable, such as plant height measured in centimeters.
- Controlled variables
- The conditions kept the same for every trial so the test is fair. Examples include the same pot, soil, and amount of light for each plant.
- Hypothesis
- A testable prediction about what will happen in an experiment, often stated as an if-then sentence. Data can support it or fail to support it.
- Observation versus inference
- An observation is information gathered with the senses or tools, such as a footprint in mud. An inference is a conclusion drawn from that evidence, such as an animal walked here.
- Line graph
- A graph that plots data points and connects them with a line to show change over time. It is best when the independent variable is time or another continuous measure.