chem substancess

a physical change alters a substance without changing its ____________

composition

a ______ _______ is a transition from one state o fmatter to another and is a _________ change

phase change physicsl

a process that involves one or more substance changing into new substances is called a chemical change or ___________ __________

chemical reaction

the new substances formed in the reaction have different ___________ and different __________ than the substances present before the reaction

composition, properties

_______ ______ (ionic or covalent) are ___________ and or _________ during chemical reactions

chemical bonds formed broken

examples of chemical change

decomposing rusting exploding burning oxidizing combustion souring ripening baking digesting cooking

evidence of chemical reactions

temp change, color change, production of gas/bubbles, formation of precipitate, odor change, creation of liwuid

there is always a net _______ ________ between _________ and ______ when a chemical reaction occurs

energy charge reactant product

exothermic energy ____ ____ energy in forms of ____ and ______

give off, heat, light

examples of exothermic reactions

burning firewood, dynamite, neutralization between acid and base (heat forms_

endothermic chemical reactions _______ energu (heat) from their surroundings

absorb

endothermic creactions typically feel ____ to the touch

cool

example of endothermic reactions

water reacting with ammonium nitrate, melting ice, evaporating liquid water is an endothermic PROCESS, photosynthesis

physical material consisting of atoms and compounds

matter

amount of matter in an object

mass

amount of space a object takes up

volume

how tightly packed amtter is in a space

density

anything that depends on amount of matter

extenstive porperty (mass, volume)

anything that depends on the type of matter not the amount

intensive porperty (example texture hardness boiling freezing point)

matter that has a uniform and deifinte composition

substance

substances are ___ and include individual _______ or ______

pure elements compounds

every sample of a given susbtance has identical _________ properties necause every sample has the same _______

intensive composition

expands to dill volume of container

gas

not involved in typical chemical reactions

okasma

electrons stripped from nuclei of molecules leaving mixture of postiively charged ions and free floating elections

plasma

simplest form of matter with unique set of properties

element

substances that comtain two or more elements

compound

examples of properties of compounds being different from eleemnts that make it up

sugar is sweet - carbon is bitter, oxygen and hydrogen are gasses

tables salt - sodium is explosive metal chlorine is poisonous gas

_________ can be broken down into smaller substances but _______ an not

compounds, elements

____ methods can not be used when breaking down compounds it must be ______

physical, chemical

change that produces matter with a different composition than the original matter

chemical change

physical changes example

melting boiling sublimation evaporation freezing condensation deposition shredding dissolvingq

reactant

starting materials - ingredients

products

ending substance

in any chemical reaction matter is neither ________ nor _________ but can be __________ into new substances

created destoryed converted

the mass of the reactants is euqal to the mass of _______

products

T or F: mass of reactants is equal to mass of products in physical changes

yes. 10 g of ice meltis 10 g of water

when cemical reactions take place, _____ are broken between moolecules and ____ are rearranged to make new molecules

bonds, atoms

in the law of conservation of matter, you must not have the same ______ of each type of atom at th ebeginning ofthe reaction taht you had at the end of the reaction

number

when there is an uneven amount of ____ a chemical equation must be balanced

atoms

a physical blend of tow or more substances

mixture

this mixtures composition is not uniform ingredients not evenly distirbuted

heterogenous mixture

this mixture is uniform throughout

homogenous mixture

another name for a homogenous mixture

a solution

some homogenous mixtures are liquisd but some can be _____________-

gasses and solids

substance that dissolves something else

solvent

substance that gets dissolved

solute

when solute and solvent are the same phase (i.e both liquid) the substance with th elargest quantity is the solvent) T or F

true

fixed/pure substance meaning

a form of matter that has a constant, uniform composition

if the composition of a material if fixed and pure it is

`substance

if the composistion of a material varies it is a

mixture

exampele of fixed materil

distilled water carbon and propane

example of variable materials

milk and salt water and trail mix

decanting

pouring a liquid from one container into another to separate it

filtration vs distillation

Filtration separates solid particles from fluids using a physical barrier

separate liquids by heating them into a vapor and then cooling the vapor back into a liquid

true or false: solids are compressible

false they are nearly incompressible

when solids are haeted kinetic energy of particles is increased and particles _______ more rapidly

vibrate

when average kinetic energy is high enough solid reaches it _____ point

melting

crystaline solution shape

particles are ordred 3d pattern called a CRYSTAL LATTICE

ionic solids ____ melting points

high

molecular solids ___ melting points

low melting points

what is ionic solid

Ionic solids are made of charged ions held together by strong electrical forces,

what is molecular solid

, while molecular solids are made of neutral molecules held together by weak forces

smallest group of particles within a crystla that retains geometri shape of the crystal

unit cell

whats an amphorous solid

lacks an internal ordered structure. atoms are randomly arranged have no sharp melting point

examples of amorphous solid

rubber, glass, plastics

two or more molecular forms of the same element

allotrops

allotrops have diff _____ and ____ properties bc their structures are diff

chemical and physicL

examples of allotrops

carbon. can be diamond or graophite or a buckyball

vaporization

liquid to gas

condensation

gas to liquid

freezing

liquid to solid

melting

solid to liquid

deposition

gas to solid

sublimation

solid to gas

2 types of vaporixation

evaporation: occours on surface of liquid that isnt boiling. slowly occurs at any temp

boiling: occurs when temp and average kinetic energy is high enough that all of the liquid particles have enough kinetic energy to break away from each other and become gas. happens rapidly throughout all liquid at a specific boiling point

why does evaporation occur in almost all liquids even at low temps

temperature is a measure of kinetic energy some particles have enough kinetic energy to overcome intermolecular forces

intermolecular particlesa between liquid particles are broken during this

boiling

only some of the particles vaporize at __________ but all particles vaporize at _______

evaporation, boiling

changes in ______- affect boil temp

altitude

higher elevations have ______ atmospheric pressures

lower

sea level is what kPA

101.3 kPa

when atmospheric pressure is _____, there is ___ force pushing down on the liquid particles

lower, less

sublimation occurs in solids with ____ pressures that exceed _______ pressure at or near room temp

vapor atmospheric

describes the only set of conditions at which all three phases can exist in equilibrium with one another

triple point

indicates temp and pressure above which substance exists as a supercritical fluid

critical point

any substanec above its critical point where distinct gas and liquid phases do not exist

supercticial fluid

gives the conditions and temp and pressure at which a substanc exists as a solid liquid and gas

phase diagram