Rock cycle and chem

Matter

Anything that has mass and takes up space.

Atoms

The smallest unit of an element.

Elements

Pure substances made of only one type of atom.

Molecules

Two or more atoms bonded together.

Compounds

Substances made from two or more different elements chemically joined.

Mixtures

Two or more substances physically combined (not chemically).

Physical Change

Changes in state or form; no new substance formed.

Examples of physical changes

Melting, boiling, dissolving, crushing.

Chemical Change

New substances are formed.

Signs of chemical change

Colour change, gas produced, temperature change, precipitate forms.

Indicators of energy change

Exothermic (releases heat), endothermic (absorbs heat).

Chemical Equations

Show reactants → products.

Igneous Rock

Formed from cooling magma/lava.

Sedimentary Rock

Formed from weathering, erosion, compaction & cementation of sediments.

Metamorphic Rock

Formed from heat and pressure acting on existing rock.

Rock Cycle

Rocks change type through melting, cooling, weathering, and metamorphism.

Continental Drift

Continents move slowly over time, evidenced by matching fossils and rock formations.

Plate Tectonics Theory

Earth’s crust is divided into plates that move on the mantle.

Divergent Boundaries

Plates move apart (volcanoes, mid-ocean ridges).

Convergent Boundaries

Plates move together (mountain ranges, subduction zones, volcanoes).

Transform Boundaries

Plates slide past each other (earthquakes).

Constructive Forces

Creates new crust (divergent).

Destructive Forces

Destroys old crust (convergent).

Faults

Cracks where rocks move.

Folds

Bending of rock layers due to pressure.