英文原文

We'll go down the column on the periodic table in group one and look at sodium. Like the lithium, the sodium is stored on mineral oil to minimize reaction with the oxygen in the air. If we remove a piece of sodium metal, we notice that it's also coated over with an oxide coating. Group one metals become softer as you go down the column. The sodium is much easier to cut than the lithium. As we cut off the oxide layer, we can see the shiny metal underneath. It coats over very rapidly with a layer of oxide. The sodium is a metal and is an excellent conductor of electricity. If we take a piece of the sodium metal and add it to water, we notice a much more rapid reaction with the water. Like lithium, the sodium is less dense in water and floats. The metal moves across the surface being pushed by the hydrogen gas that is produced. As you go down the column with group one metals, the melting point of the metal decreases. The reaction is very exothermic, which causes the sodium metal to melt. The metal contracts into a very compact spherical form. We can again test that hydrogen gas is being produced by this single displacement reaction by trapping the gas and testing its flammability. We can test for the fact that we produce sodium hydroxide by adding phenethylene. The phenethylene turns a purple-red color due to the presence of the hydroxide ions indicating the formation of the sodium hydroxide

中文翻譯

我們將沿著周期表中第一族元素進(jìn)行下去，看看鈉。與鋰一樣，鈉儲(chǔ)存在礦物油中，以最小化與空氣中的氧氣反應(yīng)。如果我們?nèi)〕鲆粔K鈉金屬，我們會(huì)注意到它上面也覆蓋著一層氧化物涂層。第一族金屬隨著向下移動(dòng)，變得更加柔軟。鈉比鋰更容易切割。當(dāng)我們切掉氧化層時(shí)，可以看到閃亮的金屬。它迅速被一層氧化物覆蓋。鈉是一種金屬，是優(yōu)秀的導(dǎo)電體。如果我們將一塊鈉金屬放入水中，我們會(huì)注意到它與水的反應(yīng)更加迅速。與鋰一樣，鈉在水中的密度較低，會(huì)浮起來。金屬沿著水表面移動(dòng)，受到產(chǎn)生的氫氣的推動(dòng)。隨著向下進(jìn)行第一族金屬，金屬的熔點(diǎn)降低。這個(gè)反應(yīng)是非常放熱的，導(dǎo)致鈉金屬熔化。金屬收縮成一個(gè)非常緊湊的球形形狀。我們可以通過收集氣體并測(cè)試其可燃性來再次驗(yàn)證這個(gè)單置換反應(yīng)產(chǎn)生了氫氣。我們可以通過添加苯乙烯來測(cè)試我們是否產(chǎn)生了氫氧化鈉。苯乙烯會(huì)變成紫紅色，這是由于氫氧根離子的存在，表明氫氧化鈉的形成。