Physical Science Final Exam Review - Vocabulary Flashcards

Comprehensive vocabulary flashcards covering key terms and concepts across all physical science review modules including astronomy, atomic structure, chemistry, thermodynamics, energy sources, biomolecules, and motion.

Big Bang Theory

A theory proposed by Georges Lemaître stating that the universe began from a single, very hot, extremely dense state and has continued to expand over time.

Red Shift

The phenomenon where light from distant galaxies shifts toward the red end of the EM spectrum, indicating that galaxies are moving away; used by Edwin Hubble as proof of an expanding universe.

Cosmic Microwave Background (CMB)

Thermal residue radiation present throughout space from the early hot universe after it cooled sufficiently for atoms to form.

Big Bang Nucleosynthesis

Nuclear reactions during the first few minutes of the early universe that produced light elements: mainly Hydrogen (H), Helium (He), and trace amounts of Lithium (Li).

Stellar Nucleosynthesis

Nuclear fusion reactions occurring inside the cores of living stars throughout their lifespans, forming heavier elements beyond helium up to Iron ($Fe$).

Supernova Nucleosynthesis

Nuclear reactions during the explosive deaths of massive stars (supernovae) that generate tremendous energy to forge very heavy elements like Gold, Lead, and Uranium.

Protons

Positively charged subatomic particles located inside the nucleus of an atom.

Neutrons

Uncharged neutral subatomic particles located inside the nucleus of an atom.

Electrons

Negatively charged subatomic particles orbiting outside the nucleus of an atom.

Atomic Number (Z)

The number of protons in an atom, which serves as the true basis for organizing the Periodic Table.

Mass Number (A)

The total number of protons and neutrons located inside an atom's nucleus.

Democritus

Ancient philosopher (~400 BC) who proposed the concept of "Atomos," stating that matter is composed of small, indivisible particles called atoms.

John Dalton

Scientist who formulated early scientific atomic theory, stating that matter is made of atoms, elements have unique atoms, compounds form in fixed ratios, and atoms rearrange in chemical reactions.

J.J. Thomson

Scientist who discovered the electron and proposed the Plum Pudding Model, depicting electrons embedded in a positive sphere.

Ernest Rutherford

Scientist who conducted the Gold Foil Experiment, proving that the atom is mostly empty space with a small, dense, positively charged nucleus.

Niels Bohr

Scientist who proposed the Planetary Atomic Model, stating that electrons orbit the nucleus in specific quantized energy levels.

James Chadwick

Scientist who discovered the neutron, identifying uncharged neutral particles inside the dense nucleus.

Henry Moseley

Scientist who established atomic number (proton count) as the true organizational basis for the Periodic Table.

Ionic Bonds

Bonds formed when electrons are completely transferred from a metal atom to a nonmetal atom, creating oppositely charged ions that form structured crystal lattices.

Covalent Bonds

Bonds formed when nonmetal atoms share valence electrons to achieve stability, resulting in discrete molecular units.

London Dispersion Forces (LDF)

The weakest intermolecular force, caused by temporary dipoles from fluctuating electron clouds, present in all polar and nonpolar molecules.

Dipole-Dipole Forces

Moderate intermolecular attractive forces occurring specifically between polar molecules possessing permanent dipoles.

Hydrogen Bonding

An exceptionally strong type of dipole-dipole force occurring when hydrogen is directly bonded to highly electronegative atoms: Nitrogen ($N$), Oxygen ($O$), or Fluorine ($F$).

Exothermic Reaction

A chemical reaction that releases energy (heat/light) to its surroundings, causing surrounding temperatures to increase.

Endothermic Reaction

A chemical reaction that absorbs energy from its surroundings, causing surrounding temperatures to decrease.

Photosynthesis

An endothermic reaction represented by $6CO_2 + 6H_2O + \text{Sunlight} \rightarrow C_6H_{12}O_6 + 6O_2$ that converts solar energy into chemical energy stored in glucose.

Renewable Energy Sources

Clean and sustainable energy sources naturally replenished on a human timescale, such as Solar, Wind, Geothermal, Hydropower, and Biomass.

Nonrenewable Energy Sources

Finite energy resources formed over millions of years that are depleted faster than they can regenerate, including fossil fuels (coal, petroleum, natural gas) and nuclear energy.

Carbohydrates

Biomolecules serving as the primary energy source, composed of monosaccharide monomers, and categorized into simple forms and complex polysaccharides (starch, glycogen, cellulose).

Lipids

Nonpolar and hydrophobic biomolecules responsible for long-term energy storage, insulation, and cell membrane formation (phospholipid bilayer).

Proteins

Biomolecules composed of amino acid monomers linked by peptide bonds that function as enzymes, structural components (keratin, collagen), and transporters (hemoglobin).

Nucleic Acids

Biomolecules composed of nucleotide monomers (sugar + phosphate + nitrogenous base), such as DNA and RNA, that store genetic blueprints.

Active Ingredient

The constituent in a product that performs the primary intended chemical effect, such as Sodium Hypochlorite in bleach.

Surfactants

Surface Active Agents containing a hydrophilic head and a hydrophobic tail that reduce water surface tension and trap grease/oils into micelles.

Alkaline Cleaners

Cleaning agents with a $\text{pH} > 7$ (e.g., bleach, ammonia, oven cleaner) that dissolve fats, grease, and organic stains.

Acidic Cleaners

Cleaning agents with a $\text{pH} < 7$ (e.g., vinegar, toilet bowl cleaner) that remove mineral deposits, rust, and soap scum.

Scalar

A physical quantity described by magnitude only, such as distance, speed, mass, or time.

Vector

A physical quantity described by both magnitude and direction, such as displacement, velocity, or acceleration.

Distance

The total ground covered by an object during motion; a scalar quantity that is always positive.

Displacement

The straight-line vector distance from start to end with direction, given by $\Delta x = x_f - x_i$.

Speed

The scalar rate of distance covered over time, calculated as $\text{Speed} = \frac{\text{Distance}}{\text{Time}}$.

Velocity

The vector rate of displacement over time, calculated as $\text{Velocity} = \frac{\text{Displacement}}{\text{Time}}$.

Acceleration

The rate of change of velocity over time, given by $a = \frac{\Delta v}{t}$, which occurs whenever speed or direction changes.