General Science Reviewer: Light Waves, Germ Theory, and Chemical Product Labels

A set of vocabulary flashcards covering light wave physics, the electromagnetic spectrum, Louis Pasteur's microbiology contributions, germ theory, and household chemical classifications.

Transverse Wave

A wave whose oscillations are perpendicular to the direction of wave travel, such as light.

Photons

Tiny packets of energy that light exists as in its particle nature.

Wavelength ($\lambda$)

The distance between two peaks of a wave, which determines color in visible light.

Frequency ($f$)

The number of waves passing a point in one second, measured in hertz ($\text{Hz}$).

Speed of Light ($c$)

The speed of light in a vacuum, equal to $299,792,458\,m/s$ or approximately $3 \times 10^8\,m/s$.

Amplitude

The property of a light wave related to its brightness or intensity.

Reflection

The behavior of light bouncing off a surface, such as a mirror.

Refraction

The bending of light when it enters a different medium, such as a lens.

Diffraction

The spreading of light as it passes through a narrow opening.

Interference

The phenomenon occurring when two light waves meet and either reinforce or cancel each other.

Dispersion

The separation of white light into its component visible colors, such as through a prism or in a rainbow.

Polarization

The filtering of light so that its vibrations occur in a single plane.

LiDAR

Light Detection and Ranging; a technology using light for mapping and autonomous vehicles.

Holography

A technique that uses laser light and interference to create $3D$ images.

Fiber Optics

A communication technology using light to transmit data at high speeds with low loss.

Louis Pasteur

The Father of Modern Microbiology who studied fermentation, developed pasteurization, and pioneered vaccines for chicken cholera, anthrax, and rabies.

Fermentation

A biological process in which living organisms convert sugars found in foods into alcohol, acids, and carbon dioxide ($CO_2$).

Pasteurization

A heat treatment process developed to kill living bacteria or harmful microorganisms in foods and beverages to prevent spoilage.

Pébrine

A disease affecting French silkworms caused by a protozoan parasite, investigated by Louis Pasteur in $1865$.

Germ Theory of Disease

The scientific principle stating that microscopic germs can cause infectious diseases in humans and animals.

Robert Koch

A scientist who expanded Pasteur's work and formulated a four-step method to link specific microbes to specific diseases.

Koch's Postulates

A four-step procedure (Observation & Absence, Isolation & Culture, Re-infection, Re-isolation) used to establish a causal relationship between a microorganism and a disease.

Chemical Substance

A material with a definite chemical composition, classified into elements and compounds.

Element

A chemical substance made of only one kind of atom that cannot be broken down by ordinary chemical means.

Compound

A substance formed when two or more elements chemically combine, possessing properties distinct from its constituent elements.

Surfactants

Chemical cleaning agents, such as sodium lauryl sulfate, that produce foam and remove grease, oil, and dirt.

Abrasives

Chemical components like calcium carbonate and hydrated silica used in toothpaste to gently remove stains, plaque, and food particles.

Humectants

Substances such as glycerin and sorbitol that help retain moisture and prevent personal care products from drying out.

Preservatives

Chemical ingredients like sodium benzoate and parabens that prevent the growth of bacteria and fungi, helping products remain safe and effective longer.