WHETHER HUNG ON CLASSROOM WALLS, put up in dorm rooms or screen-printed on T-shirts, the periodic table of elements screams, “Science!” like no other image. And why not? At 118 members and counting, the table lists every known chemical element, the (mostly) immutable building blocks of all materials in the universe. But it’s not just a random list of elements.The organization of the periodic table reveals an element’s behaviors and characteristics: from atomic size, density and abundance, to how it would likely interact with others. Take this opportunity to gaze upon the periodic table and see for yourself some of its hidden insights.
不管是挂在教室的墙壁上,还是在宿舍里,或是在T恤衫上贴上屏幕,周期性的元素表都会发出尖叫:“科学!”和其他图像截然不同。为什么不呢?在118个成员和计数,表格列出了每一个已知的化学元素,(大多数)不变的基石,所有物质在宇宙中。但这不是一个随机的元素列表。元素周期表的结构揭示了元素的行为和特征:从原子大小、密度和丰度,到元素如何与其他元素相互作用。利用这个机会凝视周期表,并看到自己的一些隐藏的见解
Many periodic tables include the atomic number (number of protons) and atomic weight (which depends on protons and neutrons). Sometimes they list the full name of each element, but often only include their one- or two-letter symbol, nicknames that make complicated chemical formulas more compact. If the symbol doesn’t match the name (as in Au for gold and Na for sodium), it’s likely based on the element’s original Latin name (aurum and natrium).
许多周期表包括原子序数(质子数)和原子量(取决于质子和中子)。有时,他们列出每个元素的全名,但通常只包括他们的一个或两个字母的符号,这些昵称使复杂的化学公式更加紧凑。如果该符号与名称不匹配(如金和钠的金),它很可能是基于元素的原始拉丁名称(金和钠)。
Elements in the same column often share similarities, so chemists call these groups. Roughly speaking, the farther to the right a group is, the more electrons it has ready to interact with other elements. The first group, known as the alkali metals, has just one such electron, easy to lose when reacting with an element that has more electrons, such as one from the 17th group, the halogens. The noble gases, in the last column, are so named because they’re holding about all the electrons they can, so they don’t react easily with other elements — just as the noble houses of old.
同一栏中的元素通常都有相似之处,所以化学家称之为这些组。粗略地说,一个团离右边越远,它准备与其他元素相互作用的电子就越多。第一组,被称为碱金属,只有一个这样的电子,很容易失去与元素,有更多的电子,如从第17组,卤素反应。在最后一列中,惰性气体之所以被命名,是因为它们拥有所有可能的电子,所以它们不容易与其他元素发生反应——就像古代的贵族住宅一样。
Rows in the periodic table are called periods, and we currently have seven. They list the elements in order of atomic number before cutting off and continuing again in a new row, repeating established patterns of chemical properties. The tricky part in constructing the table is knowing when they cut off — or, equivalently, how many columns (groups) to include in each row
周期表中的行称为周期,我们目前有七个。他们列出元素的顺序,原子序,然后再切断和继续在一个新的行,重复既定的化学特性模式。构建表的复杂部分是知道何时截断 —或者等效地知道每行中包含多少列(组)
Everything is made up of atoms, and atoms are made up of their own tiny particles: Electrons flit semi-randomly around a central nucleus, which is made up of neutrons and protons. (Neutrons and protons are themselves made up of other particles: quarks.) The number of protons, also called the atomic number, defines an element — alter that, and you’ve changed the element itself.
一切都是由原子组成的,原子是由它们自己的微小粒子组成的:电子以半随机的速度绕着一个由中子和质子组成的中心原子核运动。(中子和质子本身是由其他粒子组成的:夸克。)质子的数量,也称为原子序数,定义了一个元素——改变这一点,你就改变了元素本身。