The smallest unit of a chemical element, with a nucleus and electrons.

化学元素的最小单位，由原子核和电子组成。

A very small amount; the slightest trace.

极少量；丝毫。

In ancient philosophy, an indivisible particle proposed as the basic stuff of matter.

古代哲学中提出的不可再分的物质基本微粒。

An indivisible unit within a system, such as data, a symbol, or a proposition.

系统中的不可分单位，如数据、符号或命题。