period 2 element中文什么意思

第2周期元素

• period:    n. 1. 时代；期；时期；期间；阶 ...
• element:    n. 1.要素；成分；(构成)部分； ...
• period element:    元素周期; 周期元素

百科释义

A period 2 element is one of the chemical elements in the second row (or period) of the periodic table. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases; a new row is started when chemical behavior begins to repeat, creating columns of elements with similar properties.