located_in_the_administrative_territorial_entity chestnut street bridge
The Schuylkill ___MASK3___ (, locally ) is an important ___MASK3___ in ___MASK49___ and eastern ___MASK41___ . Two ___MASK81___ its tributaries drain parts ___MASK81___ the Pocono Mountains in the east and Coal Region in the ___MASK16___ ___MASK81___ the state . It flows for before joining the Delaware ___MASK3___ as its largest tributary , in Philadelphia . The Pocono Mountains , commonly referred to as the Poconos , is a geographical , geological , and cultural region located in Northeastern ___MASK41___ , United States . The Poconos are an ___MASK40___ ___MASK81___ the larger Allegheny Plateau . Forming a escarpment overlooking the Delaware River and Delaware Water Gap to the east , the mountains are bordered on the north by Lake Wallenpaupack , on the west by the Wyoming Valley and the Coal Region , and to the south by the Lehigh Valley . It comes from the Munsee word " Pokawachne ", which means " Creek Between Two Hills ." Much ___MASK81___ the Poconos region lies within the Greater New York - Newark , NY - NJ - CT - PA Combined Statistical Area . The wooded hills and valleys have long been a popular recreation area , accessible within a two - hour drive to millions ___MASK81___ metropolitan area residents , with many communities having resort hotels with fishing , hunting , skiing , and other sports facilities . In chemistry , a carbide is a compound composed ___MASK81___ carbon and a less electronegative element . Carbides can be generally classified by chemical bonding type as follows : ( i ) salt - like , ( ii ) covalent compounds , ( iii ) interstitial compounds , and ( iv ) " intermediate " transition metal carbides . Examples include calcium carbide ( CaC ), silicon carbide ( SiC ), tungsten carbide ( WC ) ( often called simply " carbide " when referring to machine tooling ), and cementite ( FeC ), each used in key industrial applications . The naming ___MASK81___ ionic carbides is not systematic . A tributary or affluent is a stream or ___MASK3___ that flows into a larger stream or main stem ( or parent ) ___MASK3___ or a lake . A tributary does not flow directly into a sea or ocean . Tributaries and the main stem ___MASK3___ drain the surrounding drainage ___MASK53___ ___MASK81___ its surface water and groundwater , leading the water out into an ocean . The Northeastern United States , also referred to as the American Northeast or simply the Northeast , is a geographical region ___MASK81___ the United States ___MASK81___ America bordered to the north by Canada , to the east by the ___MASK9___ , to the south by the Southern United States , and to the west by the Midwestern United States . The Northeast is one ___MASK81___ the four regions defined by the Census Bureau for the collection and analysis ___MASK81___ statistics . The Census Bureau - defined region has a total area ___MASK81___ with ___MASK81___ that being land mass . Though lacking a unified cultural identity , the Northeastern region is the nation ' s most economically developed , densely populated , and culturally diverse region . Of the nation ' s four census regions , the Northeast is the second most urban , with 85 percent ___MASK81___ its population residing in urban areas , led by the West with 90 percent . Cobbs Creek is an tributary ___MASK81___ Darby Creek in Delaware County , ___MASK41___ , in the United States . It forms an approximate border between Montgomery County and Delaware County . After Cobbs Creek passes underneath Township Line Road ( U . S . Route 1 ), it forms the border between ___MASK5___ and Delaware County . It later joins Darby Creek before flowing into the Delaware River . Iron is a chemical element with symbol Fe ( from ) and atomic number 26 . It is a metal in the first transition series . It is by mass the ___MASK33___ common element on ___MASK99___ , forming much ___MASK81___ ___MASK99___ ' s outer and inner core . It is the fourth ___MASK33___ common element in the ___MASK99___ ' s crust . Its abundance in rocky planets like ___MASK99___ is due to its abundant production by fusion in high - mass stars , where it is the last element to be produced with release ___MASK81___ energy before the violent collapse ___MASK81___ a supernova , which scatters the iron into space . ___MASK94___ is the largest city in the Commonwealth ___MASK81___ ___MASK41___ and the fifth - most populous city in the United States , with an estimated population ___MASK81___ 1 , 567 , 442 and more than 6 million in the seventh - largest metropolitan statistical area , . ___MASK94___ is the economic and cultural anchor ___MASK81___ the Delaware Valleya region located in the Northeastern United States at the confluence ___MASK81___ the Delaware and Schuylkill rivers with 7 . 2 million people residing in the eighth - largest combined statistical area in the United States . The Southeastern ___MASK41___ Transportation Authority ( SEPTA ) is a regional public transportation authority that operates various forms ___MASK81___ public transit services  bus , subway and elevated rail , commuter rail , light rail and electric trolleybus  that serve 3 . 9 million people in five counties in and around Philadelphia , ___MASK41___ , United States . SEPTA also manages construction projects that maintain , replace , and expand infrastructure and rolling stock . A ___MASK3___ is a natural flowing watercourse , usually ___MASK12___ , flowing towards an ocean , sea , lake or another ___MASK3___ . In some cases a ___MASK3___ flows into the ground and becomes dry at the end ___MASK81___ its course without reaching another body ___MASK81___ water . Small rivers can be referred to using names such as stream , creek , brook , rivulet , and rill . There are no official definitions for the generic term ___MASK3___ as applied to geographic features , although in some countries or communities a stream is defined by its size . Many names for small rivers are specific to geographic location ; examples are " run " in some parts ___MASK81___ the United States , " burn " in Scotland and northeast England , and " beck " in ___MASK17___ England . Sometimes a ___MASK3___ is defined as being larger than a creek , but not always : the language is vague . ___MASK10___ Philadelphia ( formerly Kingsessing Township ) is a section ___MASK81___ Philadelphia , ___MASK41___ , United States . The section can be described as extending from the western side ___MASK81___ the Schuylkill River to the city line , with the SEPTA . The ___MASK17___ border is defined by the Philadelphia City Planning Commission as east from the city line along Baltimore Avenue moving south along 51st Street to Springfield Ave . It follows the train tracks until 49th Street . From 49th and Kingsessing Ave the line moves east along Kingsessing Ave . The line then moves south along 46th St to Paschall Ave where it jogs to join Grays Ferry where the line runs to the Schuylkill River . The Coal Region is a historically important coal - mining area in Northeastern ___MASK41___ in the ___MASK49___ Appalachian Mountains , comprising Lackawanna , Luzerne , ___MASK24___ , Carbon , Schuylkill , ___MASK21___ , and the extreme northeast corner ___MASK81___ Dauphin counties . Academics have made the distinction North Anthracite Coal Field and South Anthracite Coal Field ( each ___MASK81___ ___MASK41___ ), the lower region bearing the further classification Anthracite Uplands in physical geology . The Eastern United States , commonly referred to as the American ___MASK97___ or simply the ___MASK97___ , is a region roughly coinciding with the boundaries ___MASK81___ the United States established in the 1783 Treaty ___MASK81___ Paris , which bounded the new country to the west along the Mississippi River . It is geographically diverse , spanning the Northeast and Southeast as well as the eastern part ___MASK81___ the Central United States . Cast iron is a group ___MASK81___ iron - carbon alloys with a carbon content greater than 2 %. Its usefulness derives from its relatively low melting temperature . The alloy constituents affect its colour when fractured : white cast iron has carbide impurities which allow cracks to pass straight through ; grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks ; ductile cast iron has spherical graphite " nodules " which stop the crack from further progressing . ___MASK41___ ( ___MASK41___ German : " Pennsylvaani "), officially the Commonwealth ___MASK81___ ___MASK41___ , is a state located in the northeastern and Mid - Atlantic regions ___MASK81___ the United States . The Appalachian Mountains run through its middle . The commonwealth borders Delaware to the southeast , Maryland to the south , West Virginia to the southwest , Ohio to the west , Lake Erie and the Canadian province ___MASK81___ Ontario to the northwest , New York to the north , and New Jersey to the east . Graphite , archaically referred to as plumbago , is a crystalline form ___MASK81___ carbon , a semimetal , a native element mineral , and one ___MASK81___ the allotropes ___MASK81___ carbon . Graphite is the most stable form ___MASK81___ carbon under standard conditions . Therefore , it is used in thermochemistry as the standard state for defining the heat ___MASK81___ formation ___MASK81___ carbon compounds . The ___MASK18___ River is a major river on the Atlantic coast ___MASK81___ the United States . Its watershed drains an area ___MASK81___ in five U . S . states  New York , New Jersey , ___MASK41___ , Maryland and ___MASK18___ . Rising in two branches in New York state ' s Catskill Mountains , the river flows into ___MASK18___ Bay where its waters enter the ___MASK9___ near Cape May in New Jersey and Cape Henlopen in ___MASK18___ . Not including ___MASK18___ Bay , the river ' s length including its two branches is . The ___MASK18___ River is one ___MASK81___ nineteen " Great Waters " recognized by the America ' s Great Waters Coalition . ___MASK42___ ___MASK94___ , nicknamed ___MASK42___ Philly , is a section ___MASK81___ ___MASK94___ , ___MASK41___ . Though there is no official definition ___MASK81___ its boundaries , it is generally considered to reach from the western shore ___MASK81___ the Schuylkill River , to City Avenue to the northwest , Cobbs Creek to the southwest , and the SEPTA Media / Elwyn Line to the south . An alternate definition includes all city land west ___MASK81___ the Schuylkill ; this would also include Southwest ___MASK94___ and its neighborhoods . The eastern side ___MASK81___ ___MASK42___ ___MASK94___ is also known as University City . Tin is a chemical element with the symbol Sn ( for ) and atomic number 50 , is a ___MASK43___ - transition metal in group 14 ___MASK81___ the periodic table . It is obtained chiefly from the mineral cassiterite , which contains tin dioxide , SnO . Tin shows a chemical similarity to both ___MASK81___ its neighbors in group 14 , germanium and lead , and has two main oxidation states , + 2 and the slightly more stable + 4 . Tin is the 49th most abundant element and has , with 10 stable isotopes , the largest number ___MASK81___ stable isotopes in the periodic table , thanks to its magic number ___MASK81___ protons . It has two main allotropes : at room temperature , the stable allotrope is  - tin , a silvery - white , malleable metal , but at low temperatures it transforms into the less dense grey  - tin , which has the diamond cubic structure . Metallic tin is not easily oxidized in air . The Chestnut ___MASK91___ Bridge is a bridge across the Schuylkill River that carries Chestnut ___MASK91___ in ___MASK94___ , USA . The original 1861 bridge was `` a bridge whose scale and use ___MASK81___ cast iron made it singular in the United States and throughout the world '' . The 1957 bridge , now one way , helps connect West ___MASK94___ with the rest ___MASK81___ the city . Carbon ( from " coal ") is a chemical element with symbol C and atomic number 6 . It is nonmetallic and tetravalent  making four electrons available to form covalent chemical bonds . Three isotopes occur naturally , C and C being stable , while C is a radioactive isotope , decaying with a half - life ___MASK81___ about 5 , 730 years . Carbon is one ___MASK81___ the few elements known since antiquity . The ___MASK18___ Valley is ___MASK50___ through which the ___MASK18___ River flows . By extension , this toponym is commonly used to refer to the ___MASK94___ metropolitan area (" the [ Lower ] ___MASK18___ Valley Metropolitan Area "), which straddles the Lower ___MASK18___ River just ___MASK79___ ___MASK81___ its estuary .