# Science: 8th Grade Study Guide

Essay by DayByDay1Junior High, 8th grade March 2006

Chapter 1

Experiment: this is how you can solve a problem

Hypothesis: a guess

Variable: what you use to test your hypothesis to see if it holds true

Trial: to try

Materials: what you need

Data Tables: charts, tables, graphs/anything you use to organize data(into a table)

Safety: to prevent accidents

Science: trying to understand the world around you

Chapter 8

Neutron: *think*: neutron/neutral (no charge)

Proton: positive charge *think*proton/positive

Electron: Negative charge- JUST REMEMBER!

Matter: anything that takes up space

Element: matter made up of one type of atom

Periodic Table: organizes elements by the number of protons in each elements nucleus

Types of Matter:

Mixture Element Compound

How fast is "fast"

Formula for speed: Distance divided by speed

Distance/time

Newton's laws of Motion

Law 1: Inertia: resistance to a change in motion

Law 2: Force=mass*acceleration

A=F/M

Law 3= every action has an opposite and equal reaction

Work-

Work= Force*Distance

Work: when a force moves something through a distance and the force and motion are in the same direction (power and movement)

Joule: one Newton-meter (unit for measuring work)

Machines (simple)

-WHEEL AND AXLE: (doorknob) made with different sized wheels that are connected and turn together

-INCLINED PLANE: (ramp) sloped surface used to make lifting things easier

-SCREW: (screw) an inclined plane rapped around a rod

-LEVER: moves in a fulcrum

First Class: (See-saw) Our Force....Fulcrum.......Opposing

Force {Move things}

Second Class: (wheelbarrow) Fulcrum......Opposing Force......Our Force {Easier to lift}

Third Class: (Baseball Bat) Fulcrum.......Our Force.......Opposing Force {Faster}

Movable Pulleys: 2x Easier for each x-tra wheel than a regular one.

Potential Energy- Built up energy.

Kinetic Energy- Energy of moving objects

Warmth transfers to cool energy.

Chapter 13 Static Electricity

Opposites attract

Like charges repel

Electrical Energy: the energy of charges in motion

Static Electricity: the buildup or loss of electrons...