MS-ESS2-1: Modeling the Rock Cycle and Its Energy
Also called NGSS MS-ESS2-1 · Topic: Earth's Systems · Earth and Space Science
The Official Wording
Develop a model to describe the cycling of Earth's materials and the flow of energy that drives this process.
Clarification statement: Emphasis is on the processes of melting, crystallization, weathering, deformation, and sedimentation, which act together to form minerals and rocks through the cycling of Earth’s materials.
Assessment boundary: Assessment does not include the identification and naming of minerals.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What MS-ESS2-1 Means in Plain English
Middle schoolers build a model showing how Earth's rock material is constantly recycled. Rock melts and cools into new crystals, breaks down into sediment, settles into layers, and gets squeezed and heated into new forms, driven by the sun's energy and Earth's internal heat.
The focus is the processes and the energy behind them, not naming or identifying minerals. It builds on weathering and rock layers from 4th grade (4-ESS2-1, 4-ESS1-1) and connects to plate motion and surface change (MS-ESS2-2, MS-ESS2-3).
MS-ESS2-1 I Can Statements
- I can describe how rocks change from one type to another.
- I can explain where the energy that drives the rock cycle comes from.
- I can use a model to show melting, weathering and sedimentation.
MS-ESS2-1 Worked Example
A crayon model that runs one batch of material through each stage of the rock cycle.
Can one batch of material pass through sedimentary, metamorphic and igneous forms?
Set It Up: Old crayons, a handheld pencil sharpener, foil squares, wooden blocks for pressing and a hot water bath run by the teacher.
- Shave three crayon colors into small piles.Loose shavings: weathered sediment
- Layer the colors in a foil packet and press gently with a block.Layers stick loosely: sedimentary rock
- Warm the packet in warm water, then press it hard.Colors bend and smear without melting: metamorphic rock
- The teacher floats an open packet on hotter water until it melts, then lets it cool.Colors blend into one smooth lump: igneous rock
- Shave the cooled piece to start the cycle again.New sediment from igneous rock
The same crayon wax turned into loose sediment, pressed layers, a squeezed and bent block, and finally a cooled lump.
Why it works: Earth's internal heat melts and deforms rock while sunlight drives the weather that wears it down, so material keeps cycling between rock types.
Common Mistakes with MS-ESS2-1
Thinking the cycle runs in one fixed order
“Rocks always go igneous, then sedimentary, then metamorphic.”
Try this: Any rock type can become any other. A metamorphic rock can melt, or wear down into sediment, without following a set loop.
Thinking metamorphic rock melts
“Metamorphic rock forms when rock melts underground.”
Try this: Metamorphic rock changes under heat and pressure while still solid. Once rock fully melts and cools, the result is igneous rock.
Leaving out the energy
A cycle diagram with arrows but no heat or sunlight
Try this: Label what powers each arrow. Earth's internal heat drives melting and deformation, and the sun drives weathering through wind, rain and ice.
Where MS-ESS2-1 Fits
Practice MS-ESS2-1
Quick Check
- What has to happen to a rock for it to become igneous?
- Where does the energy that weathers rock at the surface come from?
- Sandstone is buried deep and squeezed under great heat without melting. What does it become?