RISE Science Grade 6 cheat sheet

Earth's rotation on its axis (about 24 hours) causes day and night; the axis tilt of about 23.5 degrees plus revolution around the Sun causes seasons.

The Moon completes one orbit of Earth in about 28 days; the same side always faces Earth because its rotation and revolution periods match.

Moon phases in order: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent.

Solar eclipse: Moon passes between Sun and Earth (new moon). Lunar eclipse: Earth passes between Sun and Moon (full moon).

Earth's layers from outside in: crust, mantle, outer core (liquid), inner core (solid); tectonic plates are pieces of the lithosphere that float on the mantle.

Plate boundaries: divergent (plates move apart, new crust forms), convergent (plates collide, mountains or subduction), transform (plates slide past, earthquakes).

The rock cycle converts among igneous (cooled magma or lava), sedimentary (compacted layers), and metamorphic (heat and pressure) rocks.

Water cycle steps: evaporation, condensation, precipitation, runoff, and collection; the Sun supplies the energy that drives it.

Waxing means the lit portion is growing (right side lit in the Northern Hemisphere); waning means it is shrinking.

Cell parts: nucleus controls activities, mitochondria release energy from food, cell membrane controls what enters and leaves, chloroplasts carry out photosynthesis (plant cells only).

Photosynthesis: carbon dioxide + water + light energy yields glucose + oxygen; it occurs in chloroplasts and stores energy.

Cellular respiration: glucose + oxygen yields carbon dioxide + water + energy; it releases energy in mitochondria and occurs in both plants and animals.

Food chain order: producer, then consumer (primary, secondary, tertiary), then decomposer; arrows point in the direction energy flows.

In an energy pyramid only about 10 percent of energy passes to the next level, so top predators are fewest.

Biotic factors are living parts of an ecosystem; abiotic factors are nonliving parts such as water, sunlight, soil, and temperature.

A population is one species in an area; a community is all populations; an ecosystem includes the community plus abiotic factors.

Symbiosis types: mutualism (both benefit), commensalism (one benefits, other unaffected), parasitism (one benefits, other harmed).

Inherited traits come from genes passed by parents; learned behaviors are acquired through experience or observation.

Matter is anything with mass and volume; states are solid (fixed shape and volume), liquid (fixed volume, changing shape), and gas (no fixed shape or volume).

Density = mass divided by volume; an object floats in a fluid if its density is lower than the fluid's density.

Physical changes alter form but not identity (melting, dissolving); chemical changes form new substances (burning, rusting) and are often hard to reverse.

Mixtures can be separated by physical means (filtering, evaporation); compounds can be separated only by chemical means.

Newton's laws: an object at rest stays at rest unless a net force acts; force equals mass times acceleration; every action has an equal and opposite reaction.

Speed = distance divided by time; velocity includes direction; acceleration is a change in speed or direction.

Forces: balanced forces cause no change in motion; unbalanced forces cause acceleration. Friction opposes motion; gravity pulls masses together.

Energy forms include kinetic (motion), potential (stored), thermal, light, sound, and electrical; energy is conserved but can change form.

Conduction transfers heat by direct contact, convection by moving fluids, radiation by electromagnetic waves through space.

Scientific question must be testable: it identifies variables that can be measured or observed.

Independent variable is what the experimenter changes; dependent variable is what is measured; constants stay the same; a control group has no treatment.

A hypothesis is a testable prediction stated as a cause-and-effect relationship, not a guess stated as a question.

Valid conclusions require repeated trials and large sample sizes to reduce the effect of random error.

Data tables organize raw measurements; graphs show patterns: line graphs for change over time, bar graphs for comparing categories.

Correlation is not causation: two variables changing together does not prove one causes the other.

An engineering design cycle: define the problem, research, design a solution, build a prototype, test, evaluate, and redesign.

A model (diagram, simulation, physical scale model) represents a real system and has limits; it simplifies or omits some features.

Measurements should be reported with appropriate units and precision; use the metric units meters, grams, liters, and degrees Celsius.