VOA慢速英语2014 Remember Your Chemistry Classes?

 

As It Is - Remember Your Chemistry Classes?

An international team of researchers recently reported creation of a new element that is 40 percent heavier than lead.

The researchers successfully developed what they are calling Element Number 117 at a laboratory in Germany. It is identified by that number because its nucleus¹ contains that same number of particles --called protons. Element Number 117 has a temporary name -- ununseptium.

If you remember your chemistry classes in school, you will recall that about 90 elements in the Periodic Table are found in nature. But others that were created in laboratories appear only in very small amounts.

The Periodic Table lines up -- or organizes -- chemical elements in order of atomic number. The elements made in laboratories -- such as 117 -- are extremely unstable². They last only minutes before breaking down into long-lasting elements.

Creation of new elements helps scientists better-understand the chemistry and physics of atoms. But such production may also lead to the discovery of new technologies.

Russian and other scientists had reported the creation of Element 117 in 2010. But the group that confirms new elements requires at least two successful independent experiments to confirm their existence. That group -- the International Union of Pure and Applied³ Chemistry -- will give the element a permanent name.

A report on the new element appears in the journal Physical Review Letters.

1 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

2 unstable   

adj.不稳定的，易变的

参考例句：

• This bookcase is too unstable to hold so many books.这书橱很不结实，装不了这么多书。
• The patient's condition was unstable.那患者的病情不稳定。

3 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。