something so small it can no lobger be dividied . it is the basis of chemistry as atoms make up all matter. An atom has a Nucleus (protron and nuetrons) and seven shells (orbiting electrons) .
An taom is comprised of nuetrons (no charge) protons (postivie chager) and electrons (neg charge). the atomic umber is the number of electrons. the atomic mass is figured based on the toal number of tprotons and nuetrons.
is necessary to do work.
work- when a objhect is moved through a distance in response to some force; energy is transferred from one object to another
power- the rate of doing work.
Law of conservation of matter and energy
states that the sum of the matter and the energy in the universe remains the same.
heat energy and states of matter- the motion of particles wihtin a substance causes heat. all object are made up of atoms and or molecules that are in constatn state of motion. cooler is slower. hotter is faster.
melting-when a solid reaches a point at which its particles move so rapidly that they escape ther boundaries and begin got move freely.
diffusion-the movement of particles from a high concentration to an area of low concentration.
force and motion
gravity- acceleration of objects toward the center of the earth.
inertia- the stae of an object remaining at rest or in motion.
friction- the force between any two objects that come into contact with one another. friction cannot be eliminated.
energy and matter
Energy-that cannot be created or distroyed can be defined by separating it into seven catergoies which relate to the forms of physical science.
can be produced in many ways all of which cause an increase in the motion of particles of a substance.
conduction-heat moves from warmer areas to cooler areas along materials tha tconduct heat (wire and rod)
convection-heat is transferred through collisions of movlecules and occurs only in liquids and gases as they circulate.
radiation-heat is transmitted in the form of infrared radiation and ocurs only in gases and emplty space.
is controlled by vibration. the speed of sound depends upon the space between the molecules. it travels quickes throguh solids an slowest through gas.
wave-is ongitudinal movement in which the compressions and rare fractions travel spherically outward from the source.
wavelength-is the distance between two successive compressions or two successive rare fractions.
amplitude-loudness or volume
travels throgh anything that is transparent r translucent.
travels in rays (stratight lines)
the more dense the object or medium, the slower the light travels.
travels in transverse ways.
is an electromagnetic wave that is created by causeing the electron to move rapidly and emit energy.
transverse wave-has a series of crests and troughs; like dropping a pebble into still water.
wvelenght-is distance bewtween the crest or the distance between the throughs.
reflection-is caused by light rays bouncing off of a surfce.
refraction-is caused by the bending of light rays as they passed from one medium to another.
involves magnets, which have two poles (north and south) the rules of manets are similar poles repel and opp poles attract.
contains an electrical energy and a conductory
is a materail that allows electric current to flow through it (copper, gold, silver)
are material that does not allwo electric current to flow throgh it (wood, rubber, plastic)
is the amount of electricity that flows throguha a conductor
causes electron flow to do the work and ecreases flow of amperage ina circuit
is the path that an electric current flows
Series-the resisitances are connected to one another, one following another. if resistance is disconnected the circuit fails to work.
parallel-each resistance is connected to the main circuit with its own connection. if one is disconnected it still works.
electricity is a result of accumulation of elctric charges.
energy relates to that action or ower created bu use of machine
is a tool with few or no moving parts that does work. there are 6 types:
wheel and axel
magnifies force, increases speed or changes directions and is used to lift things. 3 types
1st class-fulcrum in middle or between load-scissors and seesaw
2nd class-fulcum in one end so load is in middle between fulcrum and effort-wheel barrow and stapler.
3rd class- fulcrum in end and effort betweenfulcrum and load-tweezers and fishing rod
magnifies force, used to push things apard or secure things together
magnifies force and distance increases. is used to help move things up and down and reduces the force needed.