Comprehensive Science Notes: Chemistry, Energy, and Geology

Vocabulary practice flashcards covering physical and chemical changes, heat and energy transfer, Earth's geological systems and rock types, atomic structure, and chemical bonding mechanisms.

Physical Change

A change where no new substance is formed, substance properties do not change, and which can be reversed.

Chemical Change

A change that occurs when a new substance is formed during a chemical reaction, causing atoms to rearrange.

Conservation of Mass

The principle stating that during a chemical reaction, atoms recombine into new substances and no new atoms are created or destroyed, meaning the reactants and products contain the same number of atoms.

Exothermic Reaction

A chemical reaction in which the reactants have more energy than the products, releasing extra energy to the surroundings as heat.

Endothermic Reaction

A chemical reaction in which the products have more energy than the reactants, requiring extra energy (usually heat) from the surroundings.

Conduction

The transfer of energy through solids caused by particles vibrating in place and passing energy along as heated particles vibrate more.

Convection

The transfer of thermal energy through the movement of fluids (liquids and gases) where warmer fluids become less dense and rise, while cooler fluids become denser and sink.

Radiation

The transfer of energy by electromagnetic waves that does not require particles.

Conductor

A material that allows easy thermal energy transfer.

Insulator

A material that slows down thermal energy transfer.

Energy

The ability to do work, measured in joules ($\text{J}$).

Kinetic Energy

The energy of motion, calculated using the equation $\text{KE} = \frac{1}{2}mv^2$.

Gravitational Potential Energy (GPE)

Energy stored in an object due to its position above the ground, calculated as $\text{GPE} = mgh$.

Elastic Potential Energy

Energy stored when an object is stretched or compressed.

Chemical Potential Energy

Energy stored within the chemical bonds of substances.

Open System

A system where both energy and matter can transfer in and out of the system boundaries (e.g., Earth, a cup of tea).

Closed System

A system where energy stays within the system and no matter transfers across boundaries (e.g., a sealed insulated flask).

Law of Conservation of Energy

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

Core

The innermost layer of Earth composed of iron and nickel, featuring a solid inner core and a liquid outer core.

Mantle

The thick layer of hot, semi-solid rock that flows slowly beneath Earth's crust.

Crust

The thin outermost layer of Earth that humans live on, consisting of thicker continental crust and denser oceanic crust.

Lithosphere

The rigid outer layer of Earth composed of the crust and the uppermost part of the mantle.

Divergent Boundary

A tectonic plate boundary where plates move apart (e.g., Iceland).

Convergent Boundary

A tectonic plate boundary where plates collide (e.g., Himalayas).

Transform Boundary

A tectonic plate boundary where plates slide past each other (e.g., San Andreas Fault).

Mineral

A naturally occurring solid that has a specific chemical composition.

Rock

A solid substance made up of one or more minerals combined together.

Sedimentary Rock

A type of rock formed when sediment is compacted and cemented together.

Igneous Rock

A type of rock formed when molten magma cools and solidifies.

Metamorphic Rock

A type of rock formed when an existing rock is transformed by heat and pressure without melting.

Body Fossil

A fossil formed from the preserved physical remains of an organism, such as bones.

Cast Fossil

A fossil formed when an organism leaves a mold cavity that is later filled in by minerals.

Trace Fossil

A fossil that provides evidence of an organism's activity rather than its physical body.

Amber Fossil

A fossil formed when an organism (commonly an insect) is trapped and preserved inside tree resin.

Law of Superposition

The geological law stating that in an undisturbed sequence of sedimentary rock layers, each layer is younger than the layer below it and older than the layer above it.

Element

A pure substance consisting of only one type of atom.

Compound

A substance composed of two or more different atoms chemically bonded together.

Alloy

A mixture composed of a metal combined with one or more other elements, usually another metal or carbon.

Metalloid

An element that exhibits physical and chemical properties in between those of metals and non-metals (e.g., silicon).

Atom

The smallest unit of an element that retains the chemical properties of that element.

Proton

A positively charged subatomic particle with a mass of $1$ located inside the atomic nucleus.

Neutron

A subatomic particle with no charge ($0$) and a mass of $1$ located inside the atomic nucleus.

Electron

A negatively charged subatomic particle with a mass of $0$ (or $\frac{1}{1840}$) that orbits the nucleus.

Periods

The horizontal rows that run across the periodic table.

Groups

The vertical columns that run down the periodic table, containing elements that share similar chemical properties.

Atomic Number

The total number of protons present in the nucleus of an atom.

Atomic Mass

The combined total number of protons and neutrons in an atom's nucleus.

Isotope

Forms of the same element that contain the same number of protons but different numbers of neutrons.

Cation

A positively charged ion formed when an atom loses one or more valence electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Ionic Bonding

The electrostatic attraction between positive and negative ions formed through the transfer of electrons from a metal to a non-metal.

Covalent Bonding

The chemical bonding between non-metal atoms formed when they share pairs of electrons to achieve full outer shells.

Convection Current

A circular movement pattern in a fluid driven by differences in temperature and density, where warmer fluid expands and rises while cooler fluid cools and sinks.