分 is written with the character 八 (bā), "to separate", above the 刀 (dāo) "knife" radical. The written composition of 分 illustrates the concept of dividing something by separating it into smaller portions with a knife.
The most common pronounciation of 分 is with the 1st tone "fēn". It means "divide", or a small unit of time such as in 一分钟 (yī fēn zhōng) "a minute" and is combined with other characters to form words such as: 分开 (fēn kāi) "apart", 分解 (fēn jiě) "break-down, analyze", 分析 (fēn xī) "analyze, analysis", 分子 (fēn zǐ) "molecule", and 秋分 (qiū fēn) "Fall equinox".
When 分 is pronounced in the 4th tone "fèn", it means "part" or "component", and is combined with other characters to form words such as: 成分 (chéng fèn) "ingredient", 身分 (shēn fèn) "identity, identification", 充分 (chōng fèn) "ample", and 分子 (fēn zǐ) "members of a class or group".
分 can also be found as a component in characters such as: 份 (fèn) "portion (esp. gifts, newspapers & magazines)", 粉 (fěn) "powder", and 坋 (fèn) "dust".