Cobalt is a metallic element, atomic number 27 in the period table.

钴金属元素，原子27。

And fiftieth is the correct way to write the ordinal number.

而 fiftith 才词的正确写法。

Ordinal numbers are numbers that show the order of things.

词表示的事物的顺。

You'll see a number up here, it'll be an ordinal number.

大家会看到字出现在这里，它会一词。

When you're ordering things, so when ordinal numbers like second, fifth, are used as adjectives.

当你在给某事物排时，那么这时词第二，第五，作为冠词使用。

An element's atomic number is the number of protons in its nucleus.

一种元素的原子其原子核中的质子。

There are 118 known elements, each organized by atomic number.

有118种已知的元素，每种元素都按原子排列的。

We use ordinal numbers to see which comes first.

当我们看哪先的时候，使用。

But in the Olympic games, ordinal numbers are of central importance.

但在奥运会上，才最重要的。

This is just waste of space.

而且我们很少会将看起来很累赘的直接写在日期上。

We have atomic number across the bottom.

我们在底部有原子。

The periodic table is an organized display of all the chemical elements in order by atomic number.

元素周期表所有化学元素按原子有排列的表。

You can see on the periodic table that's going to be H. It's going 1 atomic number.

您可以在元素周期表中看到 H。它的原子为 1。

Ordinal numbers suggest an order of things – think the order of winners in the Olympics.

代表事物的顺--想想奥运会获胜者的顺。

Ordinal numbers can act as nouns, adjectives, or adverbs.

可以充当名词、形容词或副词。

We would find since it has a different atom number it's going to have different ratio of average masses.

我们会发现，由于它的原子不同，它的平均质量比也不同。

All of the other ordinal numbers end in a TH.

所有其他以TH结尾的词。

In both cases, the ordinal number is acting like a noun.

在这两例子中，的作用都一名词。

Ordinal numbers also can act as adverbs.

也可以充当副词。

Which of these elements, who's atomic number is six is one of the most abundant elements in the known universe?

这元素中，哪一的原子六，已知宇宙中最丰富的元素之一？