We meet the idea of an element very

We meet the idea of an element very early in our study of chemistry. The ancients suspected that there must be some very simple substances from which more complicated ones were built. At one time they thought that everything might be made up of earth, air and water; these got the name "element" which comes from the same word as "elementary" or simple.
This idea, though wrong, is still a rather important one. The first man to recognize the modern type of element was Robert Boyle in the middle of seventeenth century. His idea was that an element was just something which could not be broken down chemically into anything simpler. He knew of metals like iron, copper, tin, lead, gold and silver and non-metals like carbon and sulphur, all the gases being called "air".
In the years since Boyle first defined an element in the modern sense over one hundred different ones have been defined. Some of these are rather common and well-known but quite a lot are manmade. Examples are mendeleyevium, nobelium and laurencium. One of the first distinctions between elements was the division into metals and non-metals.
There are some pieces of evidence that one can use in order to make the distinction. Here is a summary of these:
Evidence Metals Non-metals
Appearance: Usually shiny Usually dull (except
except when powdered iodine and some forms of carbon)

Conduction of heat: Allow heat and electricity Do not allow heat or electricity
to pass through them easily to pass through them easily


Melting and Usually high (some important Usually low (exceptions:
oiling points: exceptions are sodium and carbon and silicon)
potassium)

You may be able to devise other ways of distinguishing metals from non-metals.

Результаты (английский) 3:

我们在我们的化学研究中很早就认识到了一个元素的概念。古人怀疑，一定有一些非常简单的物质，从中更复杂的是建立。有一段时间，他们认为一切都是由地球、空气和水组成的，这些人的名字叫“元素”，来自同一个词的“基本”或简单。这个想法，虽然错误，仍然是一个相当重要的一个。第一个承认现代类型的元素的人是在第十七世纪中叶的罗伯特·波义耳。他的想法是，一个元素是不能被分解成更简单的东西的东西。他知道金属如铁、铜、锡、铅、金、银和非金属，如碳和硫，所有的气体都被称为“空气”。在过去的几年中，波义耳首先定义了一个元素在现代意义上超过一百个不同的定义。这些都是一些很常见的，但是很多都是人为著名。例如mendeleyevium，锘和laurencium。元素之间的第一个区别之一是分裂成金属和非金属。有一些证据表明，人们可以使用，以使区别。这里是对这些的总结：证据金属非金属外观：通常有光泽通常是暗的（除了除粉末碘和碳的几种形式）热传导：允许热和电不允许热或电通过他们轻松地通过他们轻松熔化，通常高（一些重要的通常是低的（例外：加油点：例外的是钠、碳和硅）钾）你可以设计出其他方法来区分非金属的金属。