化学元素

gài shì duì shēng wù zhì guān zhòng yào de huà xué yuán sù

钙是对生物至关重要的化学元素。

Calcium is a chemical element that is vital to living things.

měi yī zhǒng huà xué yuán sù dōu yóu yuán zǐ zǔ chéng

每一种化学元素都由原子组成。

Every chemical element is composed of atoms.

huà xué yuán sù yòng fú hào lái biǎo shì

化学元素用符号来表示。

A chemical element is represented by a symbol.