Grade 9 Science First Term Study Flashcards

Vocabulary practice flashcards covering Unit 1 (Electricity & Circuits), Unit 2 (Electromagnetic Radiation), and Unit 3 (Plate Tectonics & Geology) from the Grade 9 Science reviewer.

Electrons

Subatomic particles whose movement in conducting wires primarily produces electricity.

Ampere (A)

The Standard International (SI) unit used to measure electric current ($I$).

Ohm's Law

The principle stating that electric current ($I$) is equal to voltage ($V$) divided by resistance ($R$), expressed as $I = V \frac{1}{R}$ or $I = V \times R^{-1}$.

Series Circuit

A circuit arrangement featuring a single continuous path where components are dependent on each other, causing all bulbs to turn off if one fails.

Parallel Circuit

A circuit arrangement featuring multiple independent branches where components operate independently, allowing other bulbs to stay lit if one fails.

Electromagnetic (EM) Waves

Transverse waves formed by electric and magnetic fields oscillating perpendicularly to each other and their direction of propagation, capable of traveling through a vacuum.

Radio Waves

Electromagnetic waves with longer wavelengths than visible light, commonly used for television and radio broadcasting.

Microwaves

Electromagnetic waves that pass through the atmosphere to carry signals, making them ideal for mobile phone communication.

Infrared (IR)

Electromagnetic radiation utilized in short-range remote controls and heat-sensing technology.

Ultraviolet (UV)

High-energy electromagnetic radiation from sunlight that can cause sunburn and biological cell damage.

X-rays

High-penetration electromagnetic radiation used to create medical images of patient bones.

Lead Shields

Protective barriers used during X-ray procedures to limit patient and technician exposure to harmful radiation.

Alfred Wegener

The scientist who proposed the Continental Drift Theory.

Glossopteris

An extinct plant species whose identical fossil remains found on distant continents serve as evidence for continental drift.

Divergent Boundary

A tectonic plate boundary where plates move apart from one another, allowing magma to rise and create new crust.

Seafloor Spreading

The geological process occurring at divergent boundaries where rising magma forms new oceanic crust as tectonic plates pull apart.

Convergent Boundary

A tectonic plate boundary where plates collide, causing one plate to be forced beneath another.

Subduction

The geological process occurring at convergent boundaries in which one tectonic plate is forced down into the mantle beneath another plate.

Transform Boundary

A tectonic plate boundary where plates slide past each other horizontally along fault lines.