Year 9 - Science - Semester 2 Exam Revision

Circuit Diagram

A diagram with symbols that shows all of the components in a circuit and how they are connected.

Electric Charge

A positive or negative charge that can carry electrical energy

Electric Circuit

A complete, unbroken path through which electric charges can flow

Current

A measurement of the number of electrons that pass a certain point in the circuit per second. Symbol (I), unit (amps/amperes)

Conductor

A material which allows charged particles (electrons) to move through it

Electrical Energy

Energy caused by the movement of electrons from negative to positive charge

Insulator

A material that does not allow charged particles (electrons) to move through it

Electrostatic Charge

An electrical charge that is trapped on an object (such as a balloon)

Parallel Circuit

A circuit that contains more than one path for electrical current to follow

Resistance

The measurement of how difficult it is for charges to flow through a material. Symbol (R), unit is ohms.

Series Circuit

A circuit in which all parts are connected side by side, to provide a single path for current to follow

Van De Graff Generator

A machine used to generate static electricity

Voltage

The difference in electrical energy between two places in a circuit. Symbol (V), units are volts (V)

Static Electricity

One type of electricity. A buildup of electrons on an object which are not able to move

Current Electricity

One type of electricity. The continuous moving flow of electrons in a complete circuit

Generator

A machine that converts mechanical energy into electrical energy by using magnets to separate charges

Ammeter

A device used to measure current in a circuit

Voltmeter

A device used to measure voltage

Ohm's Law

V=IR

Ohm's Law

I = V/R

Ohm's Law

R = V/I

Ohm's Law

Current and Voltage are directly proportional to one another, while resistance is inversely proportional to both

Magnetic metals

iron, cobalt, nickel

Energy transformation

A change from one form of energy to another

Energy transfer

Movement of energy from one place or object to another

Resistor

An electrical device that resists the flow of electrical current

Fuse

A safety device with a thin metal strip that will melt if too much current passes through a circuit

Magnet

any material that attracts iron and materials that contain iron

Light globe

Generates light when current flows through

Switch

a device that opens or closes a circuit

Connecting wire

a wire that connects different components together in a circuit

Electric motor

a device that converts electrical energy into mechanical energy

Cell (battery)

gives power to the circuit

Battery

Multiple cells connected together

Collaboration

when organisms of the same species work together to ensure their survival

Mating

when organisms of the same species produce offspring

Competition

when organisms of the same species compete over limited resources

Symbiosis

a close physical and long-term relationship between organisms of different species

Mutualism

a symbiotic relationship where both organisms benefit

Commensalism

symbiotic relationship where one organism benefits & the other is unaffected.

Parasitism

symbiotic relationship in which one organism benefits and the host is harmed

Predator

an organism that preys and consumes others

Prey

An organism that is killed and eaten by another organism

Immigration

Movement of individuals into a population

Emigration

movement of individuals out of an area

Food web

network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

Primary producer

Organisms that produce energy available for other organisms to eat

Apex predator

the top predator in an ecosystem; top of the food chain

Biosphere

Part of Earth in which life exists including land, water, and the atmosphere

Ecosystems

A biological community of interacting organisms and their physical environment. Interaction between biotic and abiotic factors.

Biotic factor

Interaction between living things

Abiotic factor

A non-living factor that shapes an ecosystem (e.g. light, temperature, water)

Habitat

Place where an organism lives

Population

A group of individuals that belong to the same species and live in the same area at the same time

Community

All the different populations that live together in the same area at the same time

Decomposer

An organism that breaks down wastes and dead organisms (e.g. fungi)

Evaporation

The physical change of a substance from a liquid to a gas

Hibernation

A period of inactivity that some animals experience in winter that allows them to survive on stored body fat

Introduced species

non-native species deliberately or accidentally introduced into a new habitat

Biological control

the control of a pest by the introduction of a natural enemy or predator.

Photosynthesis

process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

Glucose

A simple sugar that is made by plants through photosynthesis

Chlorophyll

A green pigment found in the chloroplasts of plants, algae, and some bacteria. Site of photosynthesis

Carbon dioxide

CO2 - plants breathe it in, animals breathe it out

Oxygen

O2 - animals breathe it in, plants breathe it out

Water

H2O

Cellular Respiration

process that releases energy from glucose in the presence of oxygen

UV light

Invisible light that radiates from the sun

Natural disaster

a natural event such as a flood, earthquake, or hurricane that causes great damage or loss of life.

Flood

an overflowing of a large amount of water beyond its normal confines, especially over what is normally dry land.

Drought

A long period of low precipitation

Bushfires

a fire that burns natural vegetation in forests, woodland or grassland

Pollution

the presence of or introduction into the environment of a substance or thing that has harmful or poisonous effects.

Enhanced Greenhouse Gas Effect

The strengthening of the natural greenhouse effect through human activities

Global warming

An increase in the average temperature of the earth's atmosphere (especially a sustained increase that causes climatic changes)