58 terms

# Science STAAR 8th grade Spring Benchmark Vocabulary

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independent variable
The thing you are testing and change; goes on the x-axis; there is only one.
constants
parts of the experiment must remain the same; there are multiple.
dependent variable
The result you MEASURE; goes on the y axis; there is only one.
force
Any push or pull which causes something to move or change its speed or direction; can be BALANCED or UNBALANCED;
Balanced forces
equal in size and opposite in direction
unbalanced forces
not equal in size and/or opposite in direction; a net force results.
Friction
A force that opposes or slows down motion; Caused by the physical contact between moving surfaces; The amount of depends upon the kinds of surfaces and the force pressing the surfaces together; Changes motion into heat.
Motion
A change in position of an object compared to a reference point
Speed
The rate of change in position; or distance ÷ time
Velocity
Speed plus direction
Acceleration
The rate of change in velocity
Positive acceleration
speeding up
Negative acceleration
slowing down (decelerate)
First Law (Law of Inertia)
An object at rest stays at rest or an object in motion, stays in motion (in the same direction/at the same speed) unless acted upon by an unbalanced force
Inertia
The tendency of an object to resist any change in its motion
Second law (Law of Force and Acceleration)
The greater the force, the greater the acceleration, The greater the mass, the greater the force needed for the same acceleration. Calculated by: F = ma
Third law (Law of Action-Reaction)
For every action force, there is an equal and opposite reaction force. (Forces are always paired)
Potential Energy
Energy of position
Kinetic Energy
Energy of motion
Atomic Number
The number of protons
Atomic Mass
The sum of the number of protons and neutrons
proton
Positive charge; inside the nucleus- identifies the atom; 1 atomic mass unit
electron
Negative charge; in electron cloud / orbiting around nucleus- determines reactivity of element; Almost zero mass: 1/1836 amu!
neutron
Neutral charge; inside the nucleus- just adds mass/weight; 1 atomic mass unit
nucleus
center of atom; contains protons and neutrons
electron cloud
outer part of atom; contains electrons
Periods
tell the number of electron rings
Group number
number of valence electrons
Chemical Property
ability of an element or compound to react with another substance.
H-R Diagram
Shows the relationship between color, temperature, magnitude & size of stars
Spiral Galaxy
a galaxy with a bulge in center & distinctive spiral arms
Elliptical Galaxy
a spherical or elongated galaxy
Irregular Galaxy
any other type of galaxy
Full moon
all of surface facing Earth is illuminated by the Sun
New moon
moon is between Earth & Sun, so lit portion is facing away from Earth
Waxing moon
lit portion of the moon is "growing"
Waning moon
lit portion of the moon is "decreasing"
Gibbous moon
larger than ½ of the moon lit
Crescent moon
smaller than ½ of the moon lit
Tide
daily rise & fall in ocean water level
Spring tides
moon and sun pull together = largest tides
Neap tide
moon and sun pull against each other = weakest tides
Rotation
spin of object on its axis; responsible for day vs. night
Revolution
path of one object around another; also called an orbit
energy from the sun
Weather
condition changes from day to day
Climate
a region's general pattern of weather over a long period of time.
Convection
cool air (or water) is more dense than warm, so it sinks, creating currents
Air mass
A body of air that has similar pressure, temperature, & humidity
Front
where two air masses meet or collide
Surface currents
water movement on the surface of oceans caused by: Winds, Continental deflections, & the Coriolis Effect
Deep ocean currents
water movement of oceans caused by: Temperature differences, Salinity differences, and density
Current
movement of water in the ocean
global conveyor belt
Movement of currents is constant and transfers heat from one part of the Earth to another via water.
Low pressure
cloudy and often rainy conditions
High pressure
clear and pleasant skies. High means dry...
Cold fronts
move from poles toward equator- have triangle flags (think icicles)
Warm fronts
move from equator toward poles- have half circle flags (think rising sun)