A known element, say a piece of iron, for example, is heated from pure gas flame.

一块已知的元素，比如说铁，会在纯净的气体下燃烧，一直加热到有射线放出。

youdao

A known element, say a piece of iron, for example, is heated from pure gas flame.

一块已知的元素，比如说铁，会在纯净的气体下燃烧，一直加热到有射线放出。

youdao