WEBVTT 00:00:00.660 --> 00:00:03.120 我们人类已知存在了数千年 00:00:03.120 --> 00:00:05.341 仅仅看向我们周边的环境 00:00:05.341 --> 00:00:06.840 那里有不同的物质 00:00:06.840 --> 00:00:08.600 而这些不同的物质往往 00:00:08.600 --> 00:00:10.120 有不同的特性 00:00:10.120 --> 00:00:11.470 不仅它们有不同的特性 00:00:11.470 --> 00:00:13.400 一种可能以某一特定的方式反射光 00:00:13.400 --> 00:00:16.230 或不反射光,或特定的颜色,或 00:00:16.230 --> 00:00:20.390 在某一特定温度,成为液体或气体或固体 00:00:20.390 --> 00:00:22.290 但我们已开始观察它们如何 00:00:22.290 --> 00:00:25.030 在某些环境下相互反应 00:00:25.030 --> 00:00:27.410 而且这里是一些这些物质的图片 00:00:27.410 --> 00:00:29.070 在这里的是碳 00:00:29.070 --> 00:00:31.650 并且这里是它的石墨形式 00:00:31.650 --> 00:00:33.910 这个是铅 00:00:33.910 --> 00:00:36.030 这个是黄金 00:00:36.030 --> 00:00:38.750 并且还有我展示过的所有照片,在这里—— 00:00:38.750 --> 00:00:41.720 我从这个网站中获得它们,就在这里—— 00:00:41.720 --> 00:00:43.460 它们都处于其固体状态 00:00:43.460 --> 00:00:45.830 但我们也知道它看上去像 00:00:45.830 --> 00:00:49.240 某些类型的空气和某些类型的空气颗粒 00:00:49.240 --> 00:00:51.090 并且取决于何种种类的空气颗粒 00:00:51.090 --> 00:00:55.590 你正看着它,无论是碳或氧或氢 00:00:55.590 --> 00:00:57.790 似乎有不同种类的特性 00:00:57.790 --> 00:00:59.666 或者是还有其他可以是液体的东西 00:00:59.666 --> 00:01:02.360 或你将这些东西的温度升至足够高 00:01:02.360 --> 00:01:04.485 你可以做到,如果你将其温度升至足够高 00:01:04.485 --> 00:01:06.440 对金或对铅,你可以得到(它们各自的)液体形式 00:01:06.440 --> 00:01:10.360 或者你点燃这些碳 00:01:10.360 --> 00:01:12.020 你可以使它变成气态 00:01:12.020 --> 00:01:13.690 你可以将之释放至大气层 00:01:13.690 --> 00:01:14.880 你可以打破它的结构 00:01:14.880 --> 00:01:18.530 所以这些是我们拥有的所有,有点,人性化 00:01:18.530 --> 00:01:21.000 已观察了数千年 00:01:21.000 --> 00:01:22.530 但这影响了一个自然问题 00:01:22.530 --> 00:01:24.420 (它)曾经是一个哲学问题 00:01:24.420 --> 00:01:26.790 但现在我们可以更好一点地回答它 00:01:26.790 --> 00:01:31.320 并且那个问题是,如果你持续分解这些碳 00:01:31.320 --> 00:01:33.970 至小之又小的块,有 00:01:33.970 --> 00:01:38.930 这些东西的最小的块,最小的单元, 00:01:38.930 --> 00:01:43.314 对于这个物质而言,始终有碳原子的特性吗? 00:01:43.314 --> 00:01:44.730 如果你要,不知何故地,持续打破它 00:01:44.730 --> 00:01:46.271 不知如何,你将 00:01:46.271 --> 00:01:48.270 失去碳的这些特性 00:01:48.270 --> 00:01:50.380 然后答案是,这就是。 00:01:50.380 --> 00:01:52.030 所以只是为了得到我们的术语 00:01:52.030 --> 00:01:54.940 我们称这些不同的物质—— 00:01:54.940 --> 00:01:58.070 这些有其特定特性的纯净的物质 00:01:58.070 --> 00:01:59.960 在特定的温度和特定的反应条件下 00:01:59.960 --> 00:02:02.020 我们将之称作元素 00:02:05.210 --> 00:02:06.470 碳是一种元素 00:02:06.470 --> 00:02:07.570 铅是一种元素 00:02:07.570 --> 00:02:08.910 金是一种元素 00:02:08.910 --> 00:02:10.949 你可能说水是一种元素 00:02:10.949 --> 00:02:14.410 并且在历史上,人们将水当作元素 00:02:14.410 --> 00:02:18.250 但现在(我们认为)水是由更多基础的元素构成的 00:02:18.250 --> 00:02:21.100 是由氧元素和氢元素 00:02:21.100 --> 00:02:27.830 并且我们所有的元素都在元素周期表里列出了 00:02:27.830 --> 00:02:30.450 C 代表碳——我只想通过那些 00:02:30.450 --> 00:02:35.710 与人类息息相关的(元素),且随着时光流逝,你可能会逐渐熟悉这里所有的元素 00:02:35.710 --> 00:02:36.610 这是氧 00:02:36.610 --> 00:02:38.020 这是氮 00:02:38.020 --> 00:02:40.140 这是硅 00:02:40.140 --> 00:02:42.090 Au是金 00:02:42.090 --> 00:02:43.280 这是铅 00:02:43.280 --> 00:02:49.380 这些元素最基础的单元是原子 00:02:52.620 --> 00:02:55.050 所以如果你持续挖掘,并持续 00:02:55.050 --> 00:02:56.940 采取到越来越小的块 00:02:56.940 --> 00:02:59.739 最终你可以得到碳原子 00:02:59.739 --> 00:03:01.530 对这些东西做同样的事,最终你将 00:03:01.530 --> 00:03:02.616 得到金原子 00:03:02.616 --> 00:03:04.490 对这些东西做同样的事,最终你将 00:03:04.490 --> 00:03:05.864 你将得到一些,这种小的 00:03:05.864 --> 00:03:08.000 我词穷了,微粒 00:03:08.000 --> 00:03:09.450 你称之为铅原子 00:03:09.450 --> 00:03:11.241 你将不再能够将其分解 00:03:11.241 --> 00:03:13.560 并依旧称之为铅 00:03:13.560 --> 00:03:17.110 因其仍旧有铅的特性 00:03:17.110 --> 00:03:19.490 并给你一个想法——这是一个非常 00:03:19.490 --> 00:03:21.600 我想象能力不太行 00:03:21.600 --> 00:03:24.690 那些原子是不可思议的小 00:03:24.690 --> 00:03:26.220 不可想象的小 00:03:26.220 --> 00:03:27.750 例如,碳 00:03:27.750 --> 00:03:29.550 我的头发也是由碳构成的 00:03:29.550 --> 00:03:33.320 事实上,我大部分都是由碳构成的 00:03:33.320 --> 00:03:36.690 事实上,我大部分都是由碳构成的 00:03:36.690 --> 00:03:40.840 所以你得到我的头发——所以我的头发是碳 00:03:40.840 --> 00:03:42.262 我的头发大部分是碳 00:03:42.262 --> 00:03:43.970 所以如果你得到我的头发——就在这 00:03:43.970 --> 00:03:46.700 我的头发不是黄色的,但它与黑色对比鲜明 00:03:46.700 --> 00:03:48.280 我的头发是黑色的,但即使我那样做了(拔头发) 00:03:48.280 --> 00:03:50.270 你将不能在屏幕上见到它 00:03:50.270 --> 00:03:51.769 但如果你得到我的头发,就在这, 00:03:51.769 --> 00:03:55.820 那么我将问你,我头发内的碳原子有多少个呢 00:03:55.820 --> 00:03:57.870 所以,如果你截取我头发的横截面 00:03:57.870 --> 00:04:00.040 而不是我头发的长度,宽度 00:04:00.040 --> 00:04:03.384 那里有多少个碳原子呢 00:04:03.384 --> 00:04:04.800 你可能会猜,哦,你知道了, 00:04:04.800 --> 00:04:07.540 萨尔已经告诉我,它们很小 00:04:07.540 --> 00:04:10.016 所以这里有一千个碳原子,或一万个 00:04:10.016 --> 00:04:10.780 或十万个 00:04:10.780 --> 00:04:12.000 我将说,不 00:04:12.000 --> 00:04:14.540 那有一百万个碳原子 00:04:14.540 --> 00:04:17.579 或者你可以串一百万个碳原子 00:04:17.579 --> 00:04:21.314 横跨人类头发的平均长度 00:04:21.314 --> 00:04:22.730 这明显是个粗略值 00:04:22.730 --> 00:04:23.970 这不是确切的一百万 00:04:23.970 --> 00:04:26.860 但它给了你“一个原子是如此之小”的印象 00:04:26.860 --> 00:04:28.620 你知道,从你的头上拔一根头发 00:04:28.620 --> 00:04:31.300 并想象将一百万个东西 00:04:31.300 --> 00:04:34.440 肩并肩地排列在一起,横跨那头发 00:04:34.440 --> 00:04:37.450 不是头发的长度,是头发的宽度 00:04:37.450 --> 00:04:39.360 这甚至难以看到头发的宽度 00:04:39.360 --> 00:04:41.110 并且那将有一百万个碳原子 00:04:41.110 --> 00:04:43.180 只是顺着它 00:04:43.180 --> 00:04:46.860 现在它本身会很酷 00:04:46.860 --> 00:04:50.840 我们确实知道有这个最基本的建筑 00:04:50.840 --> 00:04:54.220 碳块,这是任何元素的最基本组成部分。 00:04:54.220 --> 00:04:57.130 但现在更清楚的是,这些基础建筑 00:04:57.130 --> 00:04:58.570 是彼此联系的 00:04:58.570 --> 00:05:02.950 碳原子是由更多基本粒子构成的 00:05:02.950 --> 00:05:07.671 金原子是由更多基本粒子构成的 00:05:07.671 --> 00:05:09.170 它们取决于,它们实际上 00:05:09.170 --> 00:05:12.870 是由这些基本粒子的排列定义的 00:05:12.870 --> 00:05:15.430 并且如果你改变这些基本粒子的数量 00:05:15.430 --> 00:05:18.430 你可以改变这些元素的性质 00:05:18.430 --> 00:05:22.810 它如何反应,你甚至可以改变元素本身 00:05:22.810 --> 00:05:25.480 并且仅是为了更好地理解它 00:05:25.480 --> 00:05:28.260 我们来谈论这些基本粒子 00:05:28.260 --> 00:05:30.365 所以你有质子 00:05:33.020 --> 00:05:36.000 并且质子决定了 00:05:36.000 --> 00:05:38.340 原子的质子数 00:05:38.340 --> 00:05:40.610 00:05:40.610 --> 00:05:43.010 00:05:43.010 --> 00:05:45.702 00:05:45.702 --> 00:05:47.660 00:05:47.660 --> 00:05:50.490 00:05:50.490 --> 00:05:52.250 00:05:52.250 --> 00:05:55.140 00:05:55.140 --> 00:05:58.950 00:05:58.950 --> 00:06:03.120 00:06:03.120 --> 00:06:05.440 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