<telo><p>alkany, skupinov² nßzev pro <a href="javascript:top.GetURL('002817');" target="_self">alifatickΘ</a> uhlovodφky s obecn²m vzorcem C<i><sub>n</sub></i>H<sub>2<i>n</i>+2</sub>; nejjednoduÜÜφ zßstupce je <a href="javascript:top.GetURL('065002');" target="_self">metan</a> (CH<sub>4</sub>), <a href="javascript:top.GetURL('027539');" target="_self">etan</a> (CH<sub>3</sub>CH<sub>3</sub>), <a href="javascript:top.GetURL('086266');" target="_self">propan</a> (CH<sub>3</sub>CH<sub>2</sub>CH<sub>3</sub>) atd. Nφzkomolekulßrnφ p. jsou plyny n. kapaliny velmi mßlo reaktivnφ v∙Φi b∞₧n²m chem. Φinidl∙m za laboratornφ tepl., reagujφ vÜak za podmφnek radikßlov²ch reakcφ (<a href="javascript:top.GetURL('041240');" target="_self">chemickΘ reakce</a>); jsou ho°lavΘ, se vzduchem n. kyslφkem tvo°φ snadno explodujφcφ sm∞si. Vysokomolekulßrnφ p. (C<sub>16</sub> a v²Üe) jsou v∞tÜinou ji₧ pevnΘ. P. se zφskßvajφ ze <a href="javascript:top.GetURL('120611');" target="_self">zemnφho plynu</a>, pop°φpad∞ <a href="javascript:top.GetURL('091780');" target="_self">ropy</a>; jsou v²chozφmi lßtkami v <a href="javascript:top.GetURL('080833');" target="_self">petrochemii</a> (<a href="javascript:top.GetURL('010144');" target="_self">benzin</a>, <a href="javascript:top.GetURL('092404');" target="_self">rozpouÜt∞dla</a> aj.); (<a href="javascript:top.GetURL('018411');" target="_self">cykloalkany</a>, <a href="javascript:top.GetURL('078515');" target="_self">parafφn</a>, <a href="javascript:top.GetURL('038546');" target="_self">homologickΘ °ady</a>). </p></telo>