Science Final REVIEW with waves

solid

definite shape and definite volume. Particles closely packed

liquid

no definite shape but a definite volume

gas

no definite shape and no definite volume

melting

change from solid to liquid

freezing

change from liquid to solid

vaporization

when particles in a liquid gain enough energy to form a gas

evaporation

vaporization that takes place only on the surface of a liquid

boiling

vaporization that occurs when a liquid changes to a gas below its surface

condensation

when particles in a gas lose enough thermal energy to form a liquid

sublimation

a change directly from solid to the gas state without becoming liquid

pressure

the force applied to a unit area of surface

deposition

a change directly from a gas to the solid state without becoming a liquid.

endothermic

absorbing thermal energy

exothermic

releasing thermal energy

motion

the act of changing location from one place to another

reference point

A place or object used for comparison to determine if an object is in motion

meter

the basic unit of length

speed

distance travelled per unit time

average speed

Total distance divided by total time

velocity

speed in a given direction

slope

The steepness of a line on a graph; rise/run

acceleration

The rate at which velocity changes

Positive acceleration

increasing speed

Negative acceleration

decreasing speed

gravity

the force that pulls objects toward each other

air resistance

force that opposes the motion of objects that move through the air

Newton's First Law of Motion

An object at rest will remain at rest, and an object moving at a constant velocity will continue moving at a constant velocit, unless it is acted upon by an unbalanced force. Another name is Law of Inertia

Newtons' Second Law of Motion

Acceleration depends on the objects mass and on the netforce acting on the object

inertia

the tendency of an object to resist any change in its motion

Newton's Third Law of Motion

For every action there is an equal and opposite reaction

momentum

mass x velocity

fluid

a material that can easily flow

density

mass/volume

work

when an object moves in the same direction in which the force is exerted; force X distance

joule

a unit of work equal to one newton-meter

power

the rate at which work is done; work/time

simple machine

device that allows you to do work in a way that is easier or more effective

input force

the force you exert on a machine

output force

the force exerted on an object by a machine

input work

input force x input distance

output work

output force x output distance

mechanical advantage

the number of times the force exerted on a machine is multiplied by the machine; output force/input force

efficiency

the ratio of the output to the input of any system; output work/input work X 100%

inclined plane

a sloping surface, such as a ramp, that reduces the amount of force required to do work

wedge

a double inclined plane that moves

screw

inclined plane wrapped around a cylinder

lever

a rigid bar pivoted about a fulcrum

fulcrum

the fixed point around which a lever pivots

wheel and axle

simple machine made from two circular objects of different diameters that are attached and rotate together

pulley

a simple machine consisting of a grooved wheel that holds a rope or a cable

compound machine

a device that combines two or more simple machines

force

a push or pull

newton

unit of force

net force

the combination of all forces acting on an object

unbalanced forces

the forces acting on an object that causes a change in velocity; making the object speed up, slow down, or change direction

balanced forces

equal forces acting on an object in oppisite directions

friction

the force that one surface exerts on another when the two rub against each other

static friction

friction that acts on objects that are not moving

sliding friction

friction that occurs when one solid surface slides over another

rolling friction

friction that occurs when an object rolls over a surface

fluid friction

friction that occurs as an object moves through a fluid

weight

the force of gravity on a person or object at the surface of a planet

free fall

the motion of a falling object when the only force acting on it is gravity

subtraction

two forces pushing AGAINST each other

addition

two forces pushing WITH each other

solution

well-mixed mixture that contains a solvent and at least one solute

suspension

a mixture in which particles can be seen and easily separated by settling or filtration

atom

Smallest particle of an element

molecule

More than one atom bonded together

element

Contains only one type of atom

compound

A substance made up of atoms of two or more different elements joined by chemical bonds

proton

a positively charged particle located in an atom's nucleus

neutron

a neutral particle located in an atom's nucleus

electron

a negatively charged particle located outside an atom's nucleus about 2000 times smaller than either a proton or neutron

periodic table

a table of the elements, arranged by atomic number, that shows the patterns in their properties

water displacement

Process for finding the volume of an irregular solid

grams

unit for measuring mass

milliliters (mL)

unit for measuring volume of a liquid

solvent

substance that does the dissolving. For example, the water when sugar dissolves in water.

heterogeneous mixture

a type of mixture in which the parts of the mixture are noticeably different from one another

homogeneous mixture

a mixture that is the same throughout

physical change

A type of change that involves the physical properties of a substance. No new substance is created.

chemical change

Process by which substances are changed into different substances with different properties

physical

chocolate melting, salt dissolving in water and painting a wall are all examples of __________________ changes

chemical

paper burning, bubbles forming when vinegar is added, and milk going sour are all examples of __________ changes

inferring

explaining or interpreting the things you observe

predicting

making a forecast of what will happen in the future based on past experience or evidence

hypothesis

possible explanation for a set of observations or possible answer to a scientific question

manipulated (independent) variable

factor in an experiment that a scientist purposely changes; also known as independent variable

responding (dependent) variable

factor in an experiment that a scientist wants to observe, which may change in response to the manipulated variable; also known as a dependent variable

thermal energy

energy of particle motion (makes things warm)

mechanical energy

energy an object has because of its motion or position

chemical energy

Energy stored in chemical bonds

electrical energy

Energy caused by the movement of electrons.

nuclear energy

The potential energy stored in the nucleus of an atom

kinetic energy

Energy of motion

potential energy

energy that is stored

Sound energy

the energy produced when sound waves move outward from a vibrating object or sound source

light energy

a form of energy that travels in waves, visible with the eye

noble gases

What do we call the group all the way to the right, on the periodic table? (see image)