Homologus series: This is a series of compounds in which all the members are similar in constitution (i.e. they contain the same functional group, if any) and therefore in chemical properties.

同系物系列：这是一个化合物系列，其中所有成员在结构上是相似的（即它们包含相同的官能团，如果有的话），因此在化学性质上也是相似的。

Each homologous series has a general formula (e.g. CnH2n 2 for the alkanes) and each member of the series differs from the next by CH2 unit in all cases.

There is a regular change in physical properties as one ascends the series for example: methane - gas, octane - liquid, and higher alkanes - solid.

每个同源系列都有一个一般的公式（例如，CnH2n 2为烷烃），并且在所有情况下，该系列的每个成员都与下一个成员有CH2单元的不同。

随着系列的上升，物理性质有规律的变化，例如：甲烷--气体，辛烷--液体，而更高的烷烃--固体。