Energy Transfers, Chemical Change, and Geological Change

Practice vocabulary flashcards covering Topic 5 (Energy Transfers and Chemical Change) and Topic 6 (Geological Change).

Energy

The capacity to cause change, measured in joules ($\text{J}$).

Law of Conservation of Energy

The principle stating that energy cannot be created or destroyed, only transferred or transformed.

Kinetic Energy

Energy that depends on mass and speed ($E_k = \frac{1}{2}mv^2$), where doubling speed makes it four times bigger.

Gravitational Potential Energy

Stored energy that depends on mass and height, calculated using $E_p = mgh$ (where $g \times 1 \text{ or } g \text{ is } g \thickapprox 9.8\,m/s^2$).

Elastic Potential Energy

Energy stored when a material is stretched or squashed, up to its elastic limit.

Temperature

The average kinetic energy of particles, measured in $^\circ\text{C}$ or $\text{K}$.

Heat (Thermal Energy)

The total energy of all particles in a substance, which also depends on the amount of substance.

Conduction

Heat transfer via particle-to-particle interactions, occurring mainly in solids.

Convection

Heat transfer occurring through circulating currents in fluids.

Radiation

Heat transfer via infrared waves, which is the only heat transfer method that works through a vacuum.

Physical Change

A change where no new substance is formed (e.g., melting, dissolving, cutting), which is usually reversible.

Chemical Change

A process where a new substance is formed, indicated by gas bubbles, colour change, precipitate, temperature change, light/sound, or smell.

Exothermic Reactions

Reactions that release energy to the surroundings, such as combustion, respiration, and hand warmers.

Endothermic Reactions

Reactions that absorb energy from the surroundings, such as photosynthesis, instant cold packs, and thermal decomposition.

Activation Energy

The minimum energy needed to start a chemical reaction.

Conservation of Mass

The principle that mass of reactants equals mass of products in a closed system.

Outer Core

The only liquid layer among the Earth's four structural layers.

Inner Core

The innermost layer of the Earth, which remains solid due to high pressure.

Wegener's Continental Drift

The theory supported by matching coastlines, identical fossils, and rock layers on continents now separated by oceans.

Divergent Boundary

A plate boundary where tectonic plates move apart, such as the mid-Atlantic ridge.

Convergent Boundary

A plate boundary where tectonic plates collide and one subducts, forming features such as the Himalayas and Andes.

Transform Boundary

A plate boundary where plates slide past each other, such as the San Andreas Fault.

Focus

The underground starting point of an earthquake.

Epicentre

The point on the Earth's surface directly above the focus of an earthquake.

Magma

Molten rock that is underground.

Lava

Magma that reaches the Earth's surface.

Igneous Rock

Rock formed by the cooling of magma or lava, such as basalt and granite.

Sedimentary Rock

Rock formed by the compaction and cementation of sediment (such as sandstone and limestone), and the only rock type that contains fossils.

Metamorphic Rock

Rock formed by the action of heat and pressure on existing rock, such as marble and slate.

Weathering

The breaking down of rock in place through physical, chemical, or biological processes.

Erosion

The process of moving broken rock pieces away by water, wind, ice, or gravity.

Deposition

The process of dropping broken rock pieces in a new place, forming landforms like beaches and river deltas.

Mineral

A naturally occurring inorganic solid.

Ore

A rock containing enough mineral to be mined profitably.

Sustainability

Using resources in a way that allows future generations to still meet their needs.

Index Fossils

Fossils of organisms that lived for a short time over a wide area, used to date rock layers.

Transitional Fossils

Fossils that show in-between features, such as Archaeopteryx and Tiktaalik.

K-Pg Extinction

A mass extinction that occurred approximately $66\text{ million years ago}$ and wiped out non-bird dinosaurs.

Permian-Triassic Extinction

The largest mass extinction event in Earth's history, occurring approximately $252\text{ million years ago}$.