USVI NGSS Science Grade 5 cheat sheet

Matter is made of particles too small to see; this particle model explains how matter behaves when it is heated, cooled, dissolved, or mixed.

In a closed system, total mass stays the same through melting, freezing, dissolving, evaporation, and mixing: mass of parts = mass of whole (50 g water + 5 g salt = 55 g salt water).

In an open system, measured mass can drop because matter escapes as gas or vapor; the matter still exists somewhere else.

Density = mass ÷ volume; density can be used, along with color, hardness, reflectivity, conductivity, and magnetism, to identify a material.

Heating a substance can change its state (solid to liquid to gas) and cooling reverses it; state changes are reversible and do not create new substances.

Evidence that mixing two substances made a new substance: gas bubbles, color change, new smell, a solid forming, or a temperature change not caused by heating.

Melting, dissolving, and evaporating are physical changes; burning, rusting, and baking are chemical changes that produce substances with different properties.

Standard measurements: mass in grams (balance), liquid volume in milliliters (graduated cylinder), solid volume in cubic centimeters; 1 mL of water has a mass of about 1 g.

Gravity is a force that pulls every object toward Earth's center, regardless of the object's mass or whether it is moving.

Any two objects pull on each other with gravity; the pull is stronger for larger masses and weaker as the distance between objects increases.

Mass is the amount of matter (grams); weight is a measure of the gravitational pull on that mass, so weight changes if gravity changes but mass does not.

Air resistance and friction push against motion; in a vacuum with no air, a heavy and a light object dropped together hit the ground at the same time.

Forces have both strength and direction, and arrows are used to show them; equal forces in opposite directions are balanced.

Decision rule: balanced forces cause no change in motion; unbalanced forces cause a change in speed or direction.

An object in motion on Earth slows and stops because friction and air resistance act on it, not because motion naturally 'runs out'.

Magnetic force and gravity can act at a distance without the objects touching; contact forces like friction and pushes require touching.

Energy can be moved from place to place by moving objects, sound, light, and electric currents.

Energy forms include motion, light, sound, heat, electric current, and chemical energy stored in food and fuels.

The Sun is the main source of energy for Earth; almost all food and weather energy traces back to sunlight.

Plants transfer light energy into chemical energy stored in food during photosynthesis; animals obtain that energy by eating plants or other animals.

Energy transfer chain rule: Sun → producer → consumer → decomposer, with useful energy decreasing at each step as some becomes heat.

When energy changes form, the total amount is conserved, but some usually ends up as heat that spreads out and is less useful.

Food chains show one path of energy; a food web shows many paths, and arrows always point from the organism being eaten to the eater.

Plants need light, water, air (carbon dioxide), and minerals to grow; they make their own food and do not eat other organisms.

Most of the material that makes a plant grow comes from water and carbon dioxide in the air, not from soil; soil supplies water and minerals.

Roots absorb water and minerals, stems transport materials, and leaves capture light energy used to make food.

Photosynthesis: light energy + water + carbon dioxide → food (sugar) + oxygen.

Environmental factors that affect plant growth include light, water, temperature, and the minerals available in the soil.

Structural features match function: roots anchor and absorb, leaves are broad and flat to catch light, and flowers are involved in making seeds.

An organism's structures and behaviors help it survive and grow in its particular environment.

Food web arrows show the direction of energy flow: from the organism being eaten to the organism that eats it.

Matter cycles through an ecosystem: producers → consumers → decomposers → soil → producers; energy flows one way, starting from the Sun.

Decomposers such as fungi and bacteria break down dead organisms and wastes, returning nutrients to the soil.

Producers (green plants, algae) make their own food from sunlight and are the entry point of energy into a food web.

Ecosystems have living (biotic) parts and nonliving (abiotic) parts: air, water, soil, sunlight, and temperature.

Prediction rule: if a top predator is removed, its prey population usually increases at first, then declines as its own food is used up.

Organisms interact through competition for resources, predation, and helpful relationships; a change to one population affects others.

Removing or adding a producer changes the whole food web, because every consumer above it depends on that energy source.

Earth rotates on its axis once about every 24 hours, causing day and night.

Earth revolves around the Sun once about every 365 days, producing the yearly cycle.

The Sun appears to rise in the east and set in the west because Earth rotates eastward.

Shadows are longest in early morning and late afternoon and shortest near noon, tracking the Sun's apparent height in the sky.

The Sun is a star; it looks far larger and brighter than other stars only because it is much closer to Earth.

Stars are always in the sky during the day but cannot be seen because sunlight is far too bright; they appear as points of light because of their great distance.

Earth's tilted axis plus its orbit changes daylight length and the Sun's apparent height, producing seasonal patterns.

Moon phases occur because the Moon orbits Earth, changing how much of its sunlit half faces Earth.

Earth's four systems: geosphere (rock and land), hydrosphere (water), atmosphere (air), and biosphere (living things); they exchange matter and energy.

Water cycle steps: evaporation, transpiration, condensation, precipitation, runoff, and infiltration/collection.

Most of Earth's water is salt water in the ocean (about 97%); only a small fraction is fresh water, and much of that is frozen in ice.

The Sun's energy drives the water cycle and weather by evaporating water and heating air and land.

Winds and ocean currents move heat and moisture around the planet, affecting climate patterns.

Water, wind, and ice erode and deposit rock and soil, shaping landforms such as valleys, canyons, deltas, and sand dunes.

Weathering breaks rock apart in place; erosion moves the broken material to a new location.

Human activities such as clearing forests, building roads, farming, and producing waste can change the air, water, soil, and living things in a region.

Renewable resources (sunlight, wind, flowing water) are naturally replaced within a human lifetime; nonrenewable resources (coal, oil, minerals) are not.

Reducing, reusing, and recycling lowers the amount of natural resources used and the amount of waste released into the environment.

Communities use science to monitor water quality, air quality, and habitat health, then plan ways to protect them.

Decision rule: to judge an environmental solution, compare data collected before and after the change, not just opinions.

Pollution or fertilizer runoff that enters a stream can travel downstream and affect organisms far from the source.

Conserving water and electricity reduces the fuel burned and water taken to supply homes and businesses.

Design process steps: define the problem, brainstorm solutions, plan and build a model or prototype, test, evaluate, and improve.

Criteria are what a design must do to succeed; constraints are limits such as time, money, materials, space, and safety.

A model or prototype can be tested instead of the finished product to save time and money and to keep testing safe.

Change only one variable at a time during testing so results can be compared fairly between designs.

Test each design more than once; repeated trials reduce the effect of measurement error and give more reliable data.

A design that fails a test still provides useful data that guides the next improvement, so designs are revised in cycles.

Compare competing solutions by scoring each one against all the criteria and constraints, not by a single feature.

Communicate results with clear data - measurements, tables, or graphs - so others can evaluate and build on the design.