First and last unit of polyethene

Is a hydrogen atom bonded to the first and the last unit of polyethene?
If yes, where does the hydrogen come from?




Yes, in [The Characterization of Linear Polyethylene SRM 1475. II. Determination of Total Methyl Content by Infrared Spectrophotometry](https://nvlpubs.nist.gov/nistpubs/jres/76a/jresv76an2p141_a1b.pdf) and references cited therein, it is confirmed that the polymer chains terminate with methyl groups (the repeating unit plus an additional hydrogen as you phrase it). 


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