8th Grade Final Exam Review Flashcards

Flashcards covering multiple-choice questions from an 8th-grade science final exam, focusing on key vocabulary and concepts.

Physical Change

A change in which a substance changes its physical appearance but not its chemical composition.

Chemical Change

A change that involves the rearrangement of atoms to form new substances.

Kinetic Energy

The energy of matter in motion.

Electromagnetic Energy

A form of energy that travels through space as waves; includes radio waves, visible light, and X-rays.

Pure Substance

A substance made up of only one kind of matter and having definite properties.

Element

A substance that cannot be broken down into simpler substances by chemical means; made of one type of atom.

Weight

A measure of the force of gravity acting on an object.

Mass

A measure of how much matter is in an object.

Density

The amount of mass contained in a given volume.

Atom

The smallest particle of an element.

Energy

The ability to do work or cause change.

Endothermic Change

A change in which energy is absorbed.

Exothermic Change

A change in which energy is released.

Chemical Bond

The force that holds atoms together in a molecule.

Graduated Cylinder

A graduated cylinder is used to measure volumes of liquid.

Matter

Anything that has mass and takes up space.

Density Calculation

Density is calculated by dividing mass by volume.

Mixture

A combination of substances that are physically mixed but not chemically combined.

States of Matter

The different forms in which matter can exist (solid, liquid, gas).

Physical Property

A characteristic of a substance that can be observed without changing the substance.

Chemical Property

A characteristic of a substance that describes its ability to change into different substances.

Chemical Formula

A way to represent a compound using chemical symbols and numbers of atoms.

Mendeleev's Periodic Table

Arranging elements by increasing atomic mass.

Models of Atoms

Scientists create these to describe atoms.

Properties of Metals

Metals are good conductors of heat and electricity and show a wide range of chemical properties.

Reactive Metals

The most reactive metals; Group 1.

Particle Accelerators

Machines used to make most synthetic elements.

Metals

The largest group of elements; includes metals.

Ductile

Can be pulled into a long wire.

Atoms

The number of protons equals the number of electrons in an atom.

Elements Properties

Elements have properties that change in a pattern.

Periodic Table Columns

Elements in the same column have similar properties.

Atomic Number

The number of protons in an atom (also its atomic number).

Electrons

Electrons move around the nucleus.

Atomic Number

The number of protons in its nucleus determines this.

Mendeleev's Prediction

Mendeleev predicted the properties of three new elements.

Alkaline Earth Metals

Calcium and Magnesium; alkaline earth metals.

Transition Metals

Includes gold, silver, copper and nickel.

Metalloids

Shares characteristics with both metals and nonmetals; metalloids.

Noble Gases

Elements that do not ordinarily form compounds; noble gases.

Electrons

Particles in atoms that have a negative electric charge; electrons.

Halogens

Fluorine, chlorine, bromine, and iodine; halogens.

Solid

Has a definite volume and a definite shape; solid.

Viscosity

The resistance of a liquid to flowing; viscosity.

Liquid

Particles are free to move in a container but remain close together; liquid.

Gas

Particles spread apart and fill all the space available to them; gas.

Gas Pressure

The force of a gas’s outward push divided by the area of the walls of the container; pressure.

Boyle's Law

Volume decreases; Boyle's Law

Particles in a Container

The greater the pressure.

Pressure Decreases

Pressure decreases.

Charles's Law

Volume increases

Inflated Balloon

Volume of the balloon decreases

Charles's Law

Temperature and volume of a gas.

Boyle's Law (Gas Pressure)

Boyle's Law.

Sublimation

A solid turns directly into a gas; sublimation.

Surface Tension

The surface of water has this due to liquids.

Freezing

The change from liquid to solid; freezing.

Freezing Point of Water

Same as its melting point.

Vaporization

Vaporization= a liquid becoming a gas.

Simmering Pot of Soup

Vaporization then condensation.

Boiling Point

The pressure of the air above the substance.

Condensation

The opposite of vaporization; condensation.

Charles's Law (Graph)

The graph demonstrates Charles's Law.

Boyle's Law (Graph Relation)

Volume and pressure of a gas.

Data Results

Increasing Variables.

Melting Snow

Sublimation causes Melting.

Increasing Temperature of Gas

Pressure Increases when temperature increases.

Fluid

A substance that flows; fluid.

Space

The amount of space a gas takes up; its volume.

Particles in a Solid

Particles are packed tightly together in fixed positions; they are solids.

Changes in Volume

Undergoes changes in volume most easily; gas

Particles Arrangement

Particles are arranged in either a crystalline or an amorphous form; solid.

Acceleration

Decreasing Mass increases Acceleration.

Friction

One surface exerts on another when the two rub against each other; friction.

Rolling Friction

Rolling Friction is bike tires on the road as you ride.

Air Resistance

Air Resistance is a type of Friction

Object Mass

An Object's mass velocity determines its momentum.

Collision

What happens when two objects collide in the absence of friction; momentum is not lost.

Force

Force = push or pull

Friction Type

Experiencing a type of friction means air resistance.

Balanced Forces

Do not change the object's motion; balanced forces.

Object Motion

The speed and direction of an object’s motion; velocity.

Acceleration

Velocity changes; acceleration.

Changing Direction

Acceleration is changing direction.

Light that has passed through a polarizing filter

Polarized Light.

Vision

Visual Light has a higher frequency than infrared rays.

A range of electromagnetic waves placed in a certain order

Electromagnetic Spectrum.

Wave Type

Gamma rays have the highest frequencies.

Light

Spectrum; visible light separated into various colors.

AM Broadcasts

On AM broadcasts, what remains constant; the frequency.

Thermograms

The images made by an infrared camera are called thermograms.

Ultraviolet Rays

Ultraviolet rays help your body produce vitamin D.

Work Done

The object must move some distance as a result of a force.

Work (Measured)

Measured in joules; work.

Inclined Plane

Ramp

Third Class Lever

Third-class lever-fishing pole

Inclined Plane

Screw

Pivot Point

Pivot point is a fulcrum.

Measured Power

Measured in watts - power.

Example of Work Done

Pushing a Child on a Swing