Physical Sciences Flashcards
Anything that has mass and occupies space
Matter
Characterized by their ability to retain their shape. They melt when heated and vaporize only slightly. All substances become ______ if cooled sufficiently.
Solids
These take the shape of their containers, yet cannot be compressed to any significant extent. Their volume is constant unless evaporation is occurring. They crystallize when chilled sufficiently; heat causes them to vaporize.
Liquids
They expand to fill any available space. A compressible fluid, with the volume determined by the pressure and temperature of the environment. The volume varies inversely with pressure.
Gases
The law stating that the volume of a gas varies inversely with pressure. If the pressure increases, the volume decreases (the opposite is also true)
Boyle’s Law
________ makes it possible for some elements and compounds to transform from a solid to a gas phase without becoming a liquid (I.e. Dry ice turning into a gas at room temperature)
Sublimination
Some gases can turn directly into a solid (e.g. The formation of frost)
Deposition
The amount of matter in a chemical substance
Mass
Divide mass by volume
Density. D=m/v
Various properties of matter in the solid phase that give it a high resistance to its shape-changing when force is applied
Hardness
Resistance to fracture or plastic (permanent) deformation due to friction from a sharp object
Scratch hardness
Resistance to plastic (permanent) deformation due to a constant load from a sharp object
Indentation hardness
Height of the bounce of an object dropped on the material, related to elasticity.
Rebound hardness
This scale is used to rate minerals 1-10 on hardness. (1=talc 10=diamond)
Moh’s scale of hardness
Characteristics that make up physical composition of a substance. (I.e. Color, form, electrical conductivity, density)
Physical properties
When water changes from a gas (vapor) to a liquid (water) to a solid (ice), but the molecules themselves do not change.
Physical change
When a substance changes into something else/whenever compounds are formed or decomposed. Usually not reversible. (I.e. Formation of rust)
Chemical change
__________ show the number of molecules or formula units of the reactants and products.
Chemical reaction
These subatomic particles have a negative charge and are attracted to positively charged protons (this attraction keeps them in orbit around the nucleus)
Electrons
These are composed of only one atom and cannot be separated into different substances except in some instances by radioactive decay or by nuclear reactions
Chemical elements
This number is equal to the number of protons in the nucleus of their atoms
Atomic number
The sum of protons and neutrons
Atomic mass
The chemical combination of two or more elements
Compounds
This chart arranges all the elements from left to right and top to bottom in order of increasing atomic number and generally coincide with their increasing atomic mass.
The periodic table of elements
Number of total known elements
117 elements
Number of naturally occurring elements (the rest are synthetic)
94
The measure of the acidity or basicity of a solution. Not an absolute scale.
The pH scale
Solutions with a pH scale less than 7.0
Acidic
Solutions with a pH greater than 7.0
Basic or alkaline
A water soluble mixture of different dyes extracted from lichens, used to test materials for acidity
Litmus
This paper turns red under acidic conditions
Blue litmus paper
This paper turns blue under acidic conditions
Red litmus paper
A substance made by combining two or more different materials without a chemical reaction occurring
Mixture
True or false: mixtures can usually be separated into their original components by mechanical means
True
The beginning of scientific wisdom.
Measurement
An expression of large numbers, easily written where N is a number between 1 and 10 and P is a power of 10
Scientific notation
The rate of change of position with time
Velocity. V=change in distance/change of time
The rate of change of velocity with time
Acceleration
Law that states “without outside forces a stationary object will never move; without outside forces, an object in motion will never stop or deviate from its course”
Newton’s first law of motion - “the law of inertia”
Law that states “the more force, the more acceleration”
Newton’s second law of motion
Law that states “for every action (applied force) there is an equal and opposite reaction”
Newton’s third law of motion
A natural phenomenon by which objects with mass attract one another
Gravitation
Refers specifically to the gravitational force exerted by the earth on objects in its vicinity
Gravity
Like poles repel each other, either pole can attract unmagnetized iron objects
Magnetism
True or false: there is no relationship between electricity and magnetism
False. An electric current generates a magnetic field; there is an intimate relationship between electricity and magnetism
A mechanical device that changes the direction or magnitude of a force; mechanisms that use mechanical advantage (aka leverage) to apply force
Simple machine
The ratio of the output to input force
Mechanical advantage
A rigid object that is used with an appropriate fulcrum or pivot point to multiply the mechanical force that can be applied to another object (I.e. Wheel barrow)
Lever
Mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel’s circumference. A rope, cable, for belt usually runs inside the groove (used to change direction of applied force, transmit rotational motion, or realize a mechanical advantage in either s linear of a rotational system of motion)
Pulley
A flat surface whose end points are at different heights, resulting in a slope. The distance traveled is increased, but amount of required force decreases; allows the same work to be done with a smaller force exerted over a greater distance.
Inclined plane
Solar, chemical, electrical, magnetic, nuclear, sound, light, and electromagnetic
Forms of energy
The ability to perform work, to move objects
Energy
The energy possessed by a moving object
Kinetic energy
An object in an unstable position has __________.
Potential energy
A form of energy that can be used to produce sound, light, heat, and power. Exists when the number of negative electrons does not equal the number of positive protons
Electricity
A flow of electrons through a wire
Electric current
The path an electric current flows. If a path is broken and there are not alternative paths for the electrons to follow, the electrons will not move. These make it possible for electric energy to operate a vast range of technology
Electric circuit
This results when electrical charges build up or increase on the surface of a material (I.e. Lightening)
Static electricity
Consists of two different means: fission and fusion
Nuclear energy
Releases energy when a heavy nucleus splits into smaller fragments. Used in power plants and nuclear bombs.
Nuclear fission
Yields energy when very light nuclei unite to a heavier nucleus (I.e. Stars derive their energy from this)
Nuclear fusion
A temperature measurement system where waters freezing point is at 0 degrees, and the boiling point is at 100 degrees
Celsius
Temperature scale that measures waters freezing point at 32 degrees and boiling point at 212 degrees.
Fahrenheit
The temperature in which Fahrenheit and Celsius scales coincide
-40 degrees.
Convert Celsius to Fahrenheit
F=(9/5)C+32
Convert Fahrenheit to Celsius
C=5/9(F-32)
Tends to move from a high temperature region to a low temperature region. May occur by the mechanisms of conduction, radiation, and convection.
Heat
The spontaneous transfer of thermal energy through matter, from a region of higher temperature to a region of lower temperature
Heat or “thermal” conduction
The electromagnetic radiation emitted from the surface of an object, which is due to the objects temperature
- generated when heat from the movement of charged particles within atoms is converted to electromagnetic radiation
Thermal radiation
Occurs when hot air is less dense than cool air and therefore rises
-heat can be transferred by the circulation of fluids due to buoyancy from changes in density (I.e. Upward flow of air due to a fire or hot object)
Convection
An electric current passes through a thin filament, heating it until it produces light. The enclosing glass bulb prevents the oxygen in the air from reaching the hot filament, which otherwise would be destroyed rapidly by oxidation
Incandescent light bulb (also called electric lamps)
A gas-discharge lamp that uses electricity to excite Mercury vapor. The excited Mercury atoms produce short wave ultra violet light that then causes a phosphor to fluoresce, producing visible light.
Fluorescent lamp (or fluorescent tube)
Explains why a objects appear bent as light passes from one transparent object to another. Responsible for rainbows!
Refraction
Refraction occurs when light waves travel from a medium with a given refractive index to a medium with another index. (E.g. A ray of light will refract as it enters and leaves glass)
Optics
This law says that for smooth surfaces, the angle at which light is incident on the surface equals the angle at which it is reflected.
Law of reflection
Energy generated from natural sources such as sunlight, wind, rain, tides, and geothermal heat. They are naturally replenished.
Renewable energy
Energy taken from finite resources that will eventually dwindle such as fossil fuels like coal, petroleum, and natural gases
Non renewable energy
Contribute to global warming. When burned, they release trapped energy in the form of carbon dioxide into the atmosphere. (May also contribute to acid rain)
Fossil fuels
The branches of natural sciences that study those nature and properties of energy and non living matter
Physical sciences
