Physical Science Flashcards
Solids
Retain shape. Melt when heated and vaporize slightly. Ex: rocks feathers wood
Liquids
Take on the shape of their containers. Cannot be compressed to any significant extent. Ex: water oil honey
Gases
Expand to fill any available space. Pressure increases the volume decreases. Ex air helium
Sublimation
Makes it possible for some elements and compounds to transition from a solid to a gas phase without becoming a liquid. Ex: dry ice when put in room temp. Changes to gas
Mass
The amount of matter in a chemical substance
Density
Determined by dividing the mass by the volume
Hardness
Refers to the various properties of matter in the solid phase that give it a high resistance to its shape changing when force is applied.
Three principal operational definitions of hardness
Scratch hardness, indentation hardness, rebound hardness
Scratch hardness
Resistance to fracture or plastic deformation due to friction from a sharp object.
Indentation hardness
Resistance to plastic deformation die to constant load from a sharp object.
Rebound hardness
Height of the bounce of an object dropped on the material, related to elasticity.
Mohs scale of hardness
Rates minerals and puts them on a scale from 1(softest)-10(hardest)
Physical properties
Are characteristics that make up the physical composition of a substance. Ex: color, form, electrical conductivity, and density
Physical changes
Changes in state from solid to liquid to gas but is not a perm change.
Chemical changes
Occurs whenever compounds are formed or decomposed. Rearrangement of atoms durning reaction that makes or breaks the chemical bond. The change is usually not reversible.
Chemical reaction
The number of molecules or formula units of the reactant and products.
Atoms
Center of and atom called: nucleus which is made up of particles called protons and neutrons. Protons have positive electrical charge. Neutrons have no charge. Electrons move around the outside and have a negative charge.
Chemic elements
Composed of only one atom and cannot be separated into different substances. Each have different number of protons.
Compounds
Formed by the chemic combination of two or more elements in a fixed ratio.
Litmus
Water soluble mixture of different dyes extracted from lichens. Often absorbed onto filter paper.
Mixture
Is a substance made by combining two or more difference materials without a chemical reaction occurring. The objects do not bond.
Length
Unit:meter
Symbol: m
Approx: 1.1yrd
Volume
Unit: liter
Symbol: l
Approx: 1.1 quart
Mass
Unit: gram
Symbol: g
Approx: 1/30 ounce
Motion
There is a constance change in the location of a body, and is described by stating an objects position, velocity, and acceleration.
Velocity
The rate of change of position with time.
V=d/t
Acceleration
The rate of change of velocity with time.
A=v/t
Newtons first law of motion
Without outside forces a stationary object will never move, and outside forces an object in motion will never stop or deviate from its course.
Newtons second law
The more force the more acceleration
Newtons third law
For every action (applied force) there os an equal and opposite reaction
Gravitation
Is a natural phenomenon by which objects with mass attract one another.
Magnetism
Displayed by permanent magnets and around electric currents.
Simple machine
Is a mechanical device that changes the direction or magnitude of a force.
Four classical simple machines
Lever Ex: wheelbarrow, baseball bat
Pulley ex: blinds
incline plane ex: ramp
Screw, threading determines the mechanical advantage of the machine
Forms of energy
Solar, chemical, electrical, magnetic, nuclear, sound, light, and electromagnetic
Electricity
A form of energy that can be used to produce sound light heat and power. Exists where the number of negative electrons does not precisely equal the number of positive protons.
Electrical circuit
Simply the path or circuit an electric current flows
Static electricity
Rests when electrical charges buildup of increase on the surface of a material
Light
Travel in perfectly straight lines as rays
Nuclear energy
Obtained by fission and fusion
Nuclear fission
Releases energy when a heavy nucleus splits into smaller fragments. Used in power plants and atomic bombs
Nuclear fusion
Yeds energy when very light nuclei unite to a heavier nucleus. Stars for example
Temp conversions
C=5/9(F - 32)
F=9/5C + 32
Heat conduction
Or thermal conduction is the spontaneous transfer of thermal energy through matter from a region of higher temp to a region of lower temp.
Thermal radiation
Electromagnetic radiation emitted from the surface of an object.
Convection
Occurs when hot air is leas dense than cool air and therefore rises.
Renewable energy
Energy generated from natural resources such as sunlight wind rain tides and geothermal heat.
Nonrenewable energy
Is energy taken from finite resources that eventually dwindle becoming too expensive or too environmentally damaging or retrieve. Ex: fossil fuels, coal, petroleum, and natural gas
Matter
Anything that has mass and occupies space.
