Grade 12 ABM Physical Science Exam Reviewer

Vocabulary review flashcards covering Quarter 1 Grade 12 ABM Physical Science key concepts, atomic theory, bonding, biomolecules, reactions, and Earth's characteristics.

Universe

Everything that exists, including space, time, matter, energy, galaxies, stars, and planets.

Big Bang Theory

Cosmological model stating the universe began in an extremely hot and dense state approximately $13.8\,billion\,years$ ago and has been expanding and cooling.

Georges Lemaître

Scientist who proposed an expanding universe and an extremely dense initial state.

George Gamow

Scientist who helped develop Big Bang cosmology and studied early-universe light-element formation.

Steady State Theory

Theory associated with Hermann Bondi, Thomas Gold, and Fred Hoyle proposing a universe with no beginning or end, with continuous expansion and creation of matter.

Cosmic Inflation

Extremely rapid expansion of space in the very early universe, associated with Alan Guth and Andrei Linde.

Nucleosynthesis

Formation of atomic nuclei or elements through nuclear processes.

Deuteron

Nucleus consisting of $1\,proton + 1\,neutron$.

Triton

Nucleus consisting of $1\,proton + 2\,neutrons$.

Stellar Nucleosynthesis

Formation of elements inside stars through nuclear reactions up to approximately iron.

Nuclear Fusion

Process in which light nuclei combine to form a heavier nucleus and release energy.

Atom

Smallest unit of an ordinary element that retains its identity.

Atomic Number (Z)

Number of protons in an atomic nucleus; identifies the element.

Mass Number (A)

Total number of protons plus neutrons in an atom.

Isotopes

Atoms of the same element with the same number of protons but different numbers of neutrons.

Cation

Positively charged ion that forms when an atom loses electrons.

Anion

Negatively charged ion that forms when an atom gains electrons.

Democritus

Philosopher who proposed that matter was made of tiny particles called atomos.

John Dalton

Proposed the Solid Sphere Model of the atom, stating that atoms of different elements differ and compounds form in whole-number ratios.

J. J. Thomson

Discovered the electron and proposed the Plum Pudding Model of the atom.

Ernest Rutherford

Proposed the Nuclear Model after the gold foil experiment demonstrated a tiny dense positive nucleus and mostly empty space.

Niels Bohr

Proposed the Bohr Model, stating that electrons occupy specific energy levels.

Henry Moseley

Established atomic number as the basis for arranging elements in the periodic table.

Döbereiner

Grouped elements with similar properties into triads.

Newlands

Proposed the Law of Octaves, stating that elemental properties repeated at intervals of approximately eight elements.

Dmitri Mendeleev

Arranged elements mainly by increasing atomic mass, left gaps, and predicted properties of undiscovered elements.

Radioactive Decay

Process by which an unstable atomic nucleus loses energy through radiation such as alpha, beta, or gamma.

Nuclear Transmutation

Changing one element into another through a nuclear reaction.

Particle Accelerator

Device using electric and magnetic fields to accelerate particles for nuclear experiments and synthesis of new elements.

Transuranium Elements

Synthetic elements with an atomic number greater than $92$.

Ionic Bond

Chemical bond formed by the transfer of electrons, usually between a metal and a nonmetal.

Covalent Bond

Chemical bond formed by the sharing of electrons, usually between nonmetals.

Metallic Bond

Chemical bond of metal atoms characterized by relatively delocalized or mobile electrons ("sea of electrons").

Electronegativity

Ability of an atom to attract shared electrons in a bond.

VSEPR Theory

Valence Shell Electron Pair Repulsion Theory; predicts molecular geometry from electron-pair repulsions around the central atom.

Miscibility

Ability of one liquid to completely mix with another liquid.

London Dispersion Forces

Intermolecular forces present in all atoms and molecules, caused by temporary electron distributions.

Dipole-Dipole Forces

Intermolecular attractions between polar molecules.

Hydrogen Bonding

Strong intermolecular force involving hydrogen directly bonded to $N$, $O$, or $F$.

Carbohydrates

Major macronutrient and primary energy source providing $4\,kcal/g$, composed mainly of $C$, $H$, and $O$.

Starch

Glucose polymer used for plant energy storage that is digestible by humans.

Cellulose

Glucose polymer forming plant cell walls/structural material that is not digestible by humans.

Lipids

Organic molecules generally insoluble in water and soluble in nonpolar/organic solvents, providing about $9\,kcal/g$.

Triglycerides

Lipids used for long-term energy composed of glycerol + $3$ fatty acids.

Eicosanoids

Lipid-derived signaling molecules commonly made from $20$-carbon fatty acids that regulate inflammation, blood vessels, clotting, and immune responses.

Prostaglandins

Lipid-derived molecules associated with inflammation, pain, fever, and blood-vessel regulation.

Thromboxanes

Lipid-derived molecules important in platelet aggregation, blood clotting, and blood-vessel constriction.

Alpha Helix ($\alpha$-Helix)

Secondary protein structure in which a polypeptide chain coils into a spiral, stabilized mainly by hydrogen bonds.

Nucleotide

Basic building block of nucleic acids consisting of a phosphate + $5$-carbon sugar + nitrogenous base.

Activation Energy

Minimum energy required for a chemical reaction to occur ($E_a$).

Catalyst

Substance that provides an alternative pathway, lowers activation energy, and increases reaction rate without being permanently consumed.

Mole

Unit equal to Avogadro's number of particles, $6.022 \times 10^{23}$.

Limiting Reactant

Reactant used up first in a chemical reaction that determines the maximum amount of product formed.

Goldilocks Zone

Region around a star where conditions may allow liquid water to exist on a planet's surface.

Galileo Galilei

Italian scientist who improved the telescope, observed Jupiter's four large moons and Venus's phases, and supported heliocentrism.