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Hi, I'm Jessica
嗨，我是Jessica
and I'm gonna be talking about a chemical demonstration today that
今天我要講的化學演示
I like to call bringin' home the bacon
叫作"養家糊口的培根"
Now before we get cookin', let's take a look at the chemist's best friend
在開始烹飪之前，我們先來看看化學家的老朋友
This is the periodic table
元素周期表
It was created in 1869 by the Russian chemist Dmitry Mendeleev
它是在1869年由俄國化學家德米特里·門捷列夫制作
back when only 65 elements were known
當時他制作的表中只有65個元素
Different elements on the periodic table
周期表中的不同元素
require different numbers of electrons to be "happy"
需要不同數目的電子才能"開心"
Electrons live in the shell surrounding atoms
電子位于原子核周圍的電子層中
and when an atom's outermost shell is filled to capacity
當原子最外層填滿電子時
the atom is "happy"
原子就會"開心"
Now hydrogen over here
這里的氫原子
has one electron in its outer shell
在最外層有一個電子
and needs just one more to fill it
它還需要一個才能填滿
Carbon has four electrons in its outer shell
碳最外層有四個電子
and needs four more, a total of eight electrons to fill it
還需要四個才能填滿，總共要八個電子
Now on the left and middle of the table, we have the medals
周期表的左側和中間是金屬元素
To get to eight electrons in their outer shell
要在最外層得到八個電子
the medals lose electrons
金屬需要失去電子
And on the right side of the table, we have nonmetals
而在周期表右側的則是非金屬元素
To get eight electrons, these elements gain electrons
要得到八個電子，非金屬元素需要獲得電子
And hydrogen is the only nonmetal that's on the left hand side of the periodic table
氫是唯一位于周期表左側的的非金屬元素
Now one way atoms get to eight electrons in their outer shell
原子在最外層得到八個電子
is through chemical bonds
需要通過化學鍵
A bond is the sharing of two electrons between two atoms
化學鍵是兩個原子之間兩個電子的共用
So carbon likes to have four bonds
碳喜歡有四個鍵
and hydrogen likes to have one
而氫喜歡有一個鍵
Knowing about where the electrons are and how they participate in bonding
了解電子在哪，以及電子如何參與到成鍵中
is central to many important things in the real world
對于理解現實世界中的各種現象非常重要
For example, unsaturated fats have a double bond
例如不飽和脂肪具有一條雙鍵
lots of electron
很多電子
and that gives them special reactivity
這讓其具有特殊的反應活性
which can lead to the spoiling of food when the bonds react with oxygen
當雙鍵同氧氣反應時，食物就會變質
