The element europium exists in nature as two isotopes:151Eu hasa mass of 150.9196amu,and 153Eu has a mass of 151.96amu.Calculate the relative abundance of the two europium isotopes.请大虾们顺便说说isotopes(同位素)的用法（公式 用途

The element europium exists in nature as two isotopes:151Eu hasa mass of 150.9196amu,and 153Eu has a mass of 151.96amu.Calculate the relative abundance of the two europium isotopes.请大虾们顺便说说isotopes(同位素)的用法（公式 用途 求《The element song》元素周期表之歌mp3版!歌词：There's antimony, arsenic, aluminum, selenium,And hydrogen and oxygen and nitrogen and rhenium,And nickel, neodymium, neptunium, germanium,And iron, americium, ruthenium, uranium,Europium, the element of THE ELEMENT怎么样 The TEXTAREA element是什么意思 求翻译“brave the element” 第五元素 THE FIFTH ELEMENT怎么样 The element of fire.Constructive,destructive. 【元素周期表之歌 the element song】 歌词急~ 元素周期表之歌 the element song mp3 Your browser does not support the canvas element The content of element type penguins must match (penguins)+ . what are some uses of the element不要翻译机 Confidence is the most important element of success physical education is vital element of the traditional education. android eclipse中的错误：The element must be a direct child of the element这个怎么解决. element是什么意思 element是什么意思