physical science final

matter

anything that occupies space

atom

smallest unit of matter

elements

cannot be broken down into any other substance

compound

made of two or more types of atoms

radiation

energy emitted from an object in the form of electromagnetic waves

wavelength

distance between successive peaks

frequency

how many waves pass a point in a given time

absorption

the energy makes the electron climb

emission

the electron falls down losing energy

UVC

stopped by atmospheres, highest energy, serious damage

UVB

stopped by ozone, has energy to break chemical bonds, direct damage

UVA

not stopped, has no energy to break bonds, indirect damage

covalent bond

2 electrons shared by 2 atoms

valence electron

electrons occupying the outermost layer

catalyst

a substance that participates ina reaction without undergoing permanent change

free radicals

spcies with one or more unpaired electrons, highly reacto\ive

troposhpere

lowest region of the atmosphere in which we live

chemical reaction

a process whereby substances called reactants transform into different subsatnce(wit different composition) called products

weatherq

instantaneous state of the atmosphere around us, short-term

climate

statistics of weather over a longer period

open system

exchanges both energy and mass with its environment

closed system

exhanges energy but not mass with its environment

energy

capacity for doing work, occurring in many forms, including radiation and heat

scatter

solar radiation dispersing forward, backward and sideways after hitting a particle

relfection

specisla case of scattering at the interface between different media, when the solar radiation striking hat interface is redirecteda

albedo

fraction of radiation redirected by an interface

ionq

atom or group of atoms that acquired a net electric charge as a result of gaining or losing one electron

cation

positivey charged ion

anion

negatively charged ion

ionic compound

contains ions in fixed proportions and set structurep

polyatomic ions

contain more than atoms

atomic mass

depends on the number of protons and neutrons in an atom

isotopes

variants of a particular chemecial element that conntain equal numbers of protons but different numvers of neutrons

carbon cycle

carbon moving through living entities, non-living entitie, in the form of a myriad of compounds

conservation of matter

matter can be neither created nor destroyed, but can change in chemical or physical form

photosynthesis

process by which plants produce organic matter and oxygen from CO2 and water using light as an energy source

respiration

reverse process by which bacteria, fungi, animals, and humans oxidize organic carbohydrates to derive their energy resulting in CO2 and water

feedbacks

in climate studies, processes in which a natural or anthropogenic driver affects the climate system by a certain amount, which in turn, changes the quantity

postive feedback

when a change in one segment of a sub-system causes a change in climate and that initial change enhances additional changes in climate; amplifying

negative feedback

a feedback that dampens an initial change in the climate system; stablizing

fuel

any solid, liquid, or gaseous substance that may be combusted to produce heat or work

fossil fuels

remains of decaying plant life

hydrocarbos

compounds composed only of the elements carbon and hydrogen

complete combustion

the necessary molar rato of C;O is present (blue flame)

incomplete combustion

less than the necessary O2 is present (yellow flame)

kinetic energy

the energy of motion

energy

the ability or capacity of matter to do work or to produce change

potetial energy

the energy of position

combustion

converts the energy stored in fuel molecules (potential) into heat(kinetic)

heat

the kinetic energy that flows from a hotter object to a colder one

temperature

the measure of average kinetic energy of the atoms present in the substance

calorimeter

exerimentally measure heat of combustion

exothermic

if a reactionreleases heat

endothermic

when a reaction absorbs heat

bond energy

the energy that must be abasorbed to break a specific bond

nuclear fission

the splitting of a large nucleus into smaller ones with the release of energy

chain reaction

a reaction where the products can become reactants

critical mass

the amount of fissionale fuel needed to sustain a chain reaction

radioactivity

spontaneous emission of radiation by certain elements

ionizing radiation

can remove electrons from atoms or molecules it hits

nonionizing radiation

cannot remove electrons from atoms or molecules it hits

half life

the time it takes for the level of radioactivity to fall to one half of its initial value

galvanic cell

a device that converts the energy released from sopntaneous chemical reactions into electrical energy

electrodes

electrical conductors that serve as sites for chemical reactionsa

anode

the electrode where oxidaion takes place

cathode

the electrode where reduction takes place

oxidation

a process in which chemical species lose electrons

reduction

a process in which a chemical species gains electrons

electricity

the flow of electrons from one region to another that is driven by the difference in potential enegry

primary batteries

half reacrions can onlt go one way, cant be rehcarged

secondary batteries

half reactions can go both ways, can be recharged

electrolyte

a solute that conducts electricty in an aqeous solution

separator

an electrical insulator placed between the electrodes that allow the flow of ions

capacity

the ability to sustain the flow of electrons

supercapacitors

two charged electrodes immersed in an electrolyte that stores energy by means of static charge

fuel cell

an electrochemical cell that converts the chemical energy to fuel directly into electricity without burning it

electromotive force

the potential energy difference between the two electrodes

biodiversity

the variety of life, typically measured at the genetic, species, and ecosystem levels

molecule

group of two or more atoms

homogeneous

a mixture where throughout the solution the composition is uniform.

heterogeneous

a mixture where throughout the solution the composition is not uniform.

greenhouse gases

gases in the earth's atmosphere that trap heat.

electromagnetic wave

created as a result of vibrations between an electric field and a magnetic field

global carbon cycle

represnts how carbon-containing substances cycle through nature