9th Grade Final Exams Review (2023/2024)

Vocabulary terms and key definitions derived from standard 9th grade curriculum exams in English, Physics, Chemistry, Biology, and Earth Science.

Papyrus

A light, portable writing material discovered by the Egyptians approximately 2,500 years ago.

Scribes

One of the few people in Ancient Egypt who were able to read and write.

Miser

A person, such as Mr. Lin, whose purpose is to make a lot of money and spend as little as possible.

Suffering

A word in the context of the Red Crescent text meaning a feeling of physical pain or misery.

Roald Amundsen

The Norwegian explorer who reached the South Pole one month before Robert Falcon Scott.

Atlas

A collection of maps, such as the one used by Al Idrissi, to show countries, geographical features, and climates.

Primitive

An adjective relating to the earliest times in history.

Enthusiast

A person who has a strong interest in a certain activity or subject.

Fluid Pressure ($P$)

A value that is proportional to the depth of the point within the fluid and the density ($\rho$) of the fluid.

Critical Angle ($\theta_c$)

The angle of incidence above which total internal reflection occurs at the boundary between two media.

Compound Microscope

An instrument consisting of two convex lenses: the objective lens and the ocular lens.

Reducing Agent

A substance in a chemical reaction that loses electrons, such as a more active metal in the activity series.

Galvanic Cell

An electrochemical cell where spontaneous chemical reactions produce electrical energy.

Anode

The electrode in a galvanic cell where oxidation occurs, typically characterized by a negative charge.

Tendons

Connective tissues characterized by a high density of collagen fibers that allow them to endure high tension.

Sensory Neurons

Nerve cells that receive signals from sensory receptors and transmit them to the central nervous system.

Biogeochemical Cycles

Processes that recycle chemical elements and molecules through the various components of an ecosystem.

Nebular Hypothesis

The theory that the solar system formed from the contraction of a giant cloud of gas and dust rotating around itself.

Sanitary Landfill

One of the most common methods for disposing of solid waste by burying it in the ground.

Biogas

A gas produced in landfills from waste, where $1\,m^3$ of it can generate approximately $1.25\,kWh$ of electricity.

Ionosphere

A layer within the atmosphere containing charged particles that reflects radio waves back towards Earth.