Grade 8 LEAP Practice – Science & Social Studies

Flashcards created for Grade 8 Science and Social Studies based on key concepts from the LEAP practice questions. All questions are definitions

Mitochondria

The organelle that produces energy in the cell.

Nucleus

The control center of the cell.

Photosynthesis

The process by which plants make food.

Carbon dioxide

The gas that plants take in during photosynthesis.

Oxygen

The gas that plants release during photosynthesis.

Potential energy

Stored energy.

Kinetic energy

Energy of motion.

Cell

The basic unit of life.

Physical change

A change that changes form without creating new substances.

Chemical change

A change that creates new substances, like rusting or burning.

Gravity

The force that pulls objects toward Earth.

Covalent bond

A bond that involves sharing electrons.

Ionic bond

A bond that involves transferring electrons.

H₂O

The chemical formula for water.

Hydrogen and oxygen

The two elements that make up water.

Ecosystem

A community of living and nonliving things interacting.

Producer

An organism that makes its own food.

Consumer

An organism that eats other organisms.

Decomposer

An organism that breaks down dead matter.

The Sun

The Earth's primary source of energy.

Tilt of the Earth’s axis

What causes the seasons.

Core

The hottest layer of Earth.

Crust

The layer of Earth that we live on.

Seismograph

The instrument that measures earthquakes.

Richter Scale

The scale that measures earthquake strength.

Weather

The daily conditions of the atmosphere.

Climate

The average weather over a long time.

Igneous rock

Rock that forms from magma.

Sedimentary rock

Rock that forms from layers of sediment.

Metamorphic rock

Rock that forms from heat and pressure.

Food chain

A model showing how energy moves through organisms.

Evaporation

The process of liquid changing into gas.

Condensation

The process of gas changing into liquid.

Water cycle

The movement of water through Earth and the atmosphere.

Friction

A force that resists motion.

Velocity

Speed with direction.

Acceleration

Change in speed or direction.

Renewable resource

A resource that can be replaced naturally.

Nonrenewable resource

A resource that cannot be replaced quickly.

Mercury

The planet that is closest to the Sun.

Mars

The planet known as the Red Planet.

Milky Way

The galaxy that we live in.

Gravitational pull of the moon

What causes tides.

Battery

A device that converts chemical energy into electrical energy.

Mass

The amount of matter in an object.

Weight

The force of gravity on an object.

Thermometer

The tool used to measure temperature.

Density

Mass divided by volume.

Legislative

The branch of government that makes the laws.

Executive

The branch of government that enforces the laws.

Judicial

The branch of government that interprets the laws.

The Constitution

The supreme law of the land.

The Bill of Rights

The first ten amendments to the Constitution.

27

The number of amendments to the Constitution.

Democracy

A system where people vote for leaders.

Republic

A government where people elect representatives.

George Washington

The first President of the United States.

Taxation without representation

A major cause of the American Revolution.

Declaration of Independence

The document declaring freedom from Britain.

1776

The year the Declaration was signed.

Thomas Jefferson

The author of the Declaration of Independence.

Civil War

Conflict fought over slavery and states’ rights.

Abraham Lincoln

The President during the Civil War.

Emancipation Proclamation

Ordered the freedom of enslaved people in the Confederacy.

Capitalism

An economic system based on private ownership.

Socialism

An economic system where government controls resources.

Supply and demand

Economic concept determining prices.

Tariff

A tax on imports.

Inflation

The increase in prices over time.

Primary source

A firsthand historical document.

Secondary source

A document analyzing history.

Migration

Movement of people.

Immigration

Moving into a new country.

Urbanization

The growth of cities.

North America

The continent the United States is on.

Atlantic Ocean

The ocean east of the United States.

Mississippi River

The longest river in the United States.

Natural resource

A resource from nature.

Physical map

A map that shows land features.

Political map

A map that shows boundaries.

Latitude line

A horizontal line on a map.

Longitude line

A vertical line on a map.

Prime Meridian

0° longitude.

Equator

0° latitude.

Citizen

A legal member of a country.

Law

A rule people must follow.

Veto

The President’s power to reject a bill.

Amendment

A change to the Constitution.

Federalism

Power shared between state and national governments.

Budget

A plan for spending money.

Command economy

An economic system controlled by the government.

Martin Luther King Jr.

A civil rights leader.

Civil Rights Movement

A movement for equal rights.

Segregation

Forced separation of races.

Suffrage

The right to vote.