Nuclear fission and fusion · 核裂变与核聚变
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| fission/ˈfɪʃn/ | 裂变 | liè biàn |
| chain reaction/tʃeɪn rɪˈækʃn/ | 链式反应 | liàn shì fǎn yìng |
| fusion/ˈfjuːʒn/ | 聚变 | jù biàn |
The power in the nucleus
- The nucleus holds a huge amount of energy.
- We release it in two opposite ways: splitting heavy nuclei, or joining light ones.
- These power nuclear stations on Earth and every star in the sky.
原子核中的力量
- 原子核蕴藏着巨大的能量。
- 我们以两种相反的方式释放它:分裂重的原子核,或结合轻的。
- 这些为地球上的核电站和天空中的每颗恒星提供动力。
Nuclear fission 裂变
- In fission, a heavy nucleus absorbs a neutron and splits into two smaller nuclei, releasing 2 or 3 neutrons and a lot of energy.
- Those neutrons can split more nuclei — a chain reaction 链式反应 — which is what a nuclear power station controls.
核裂变
- 在裂变(fission)中,一个重的原子核吸收一个中子并分裂成两个更小的原子核,释放 2 或 3 个中子和大量能量。
- 那些中子能分裂更多原子核——一个链式反应(chain reaction)——这是一个核电站控制的。

The fission chain reaction · 裂变链式反应
A neutron splits a uranium nucleus, which releases energy AND more neutrons — those split more nuclei, and so on. · 一个中子分裂一个铀原子核,它释放能量和更多中子——那些分裂更多原子核,如此循环。
Nuclear fission is when: · 核裂变是当:
Fission = splitting a heavy nucleus (after it absorbs a neutron) into two smaller nuclei, plus 2–3 neutrons and energy. · 裂变 = 把一个重原子核(在它吸收一个中子之后)分裂成两个更小的原子核,加 2–3 个中子和能量。
Nuclear fusion 聚变
- In fusion, two light nuclei join to make a heavier one, also releasing energy.
- The Sun makes its energy this way, fusing hydrogen into helium. The reaction below — two heavy forms of hydrogen (deuterium and tritium) — is the one used in fusion reactors on Earth:
- Fusion needs enormous temperatures and pressures, which is why it is so hard to do on Earth.
In fusion two light nuclei join into a heavier one, releasing a neutron and energy — the deuterium–tritium reaction used in fusion reactors
核聚变
- 在聚变(fusion)中,两个轻的原子核结合成一个更重的,也释放能量。
- 太阳这样制造能量,把氢聚变成氦。下面的反应——两种重的氢(氘和氚)——是地球上聚变反应堆所用的那种:
- 聚变需要巨大的温度和压强,这就是为什么在地球上很难做到。

在聚变中两个轻原子核结合成一个更重的,释放一个中子和能量——聚变反应堆所用的氘–氚反应
Nuclear fusion is when: · 核聚变是当:
Fusion = joining two light nuclei into a heavier one, releasing energy. It powers the Sun. · 聚变 = 把两个轻原子核结合成一个更重的,释放能量。它为太阳提供动力。
Which process powers the Sun? · 哪个过程为太阳提供动力?
The Sun fuses hydrogen nuclei into helium, releasing huge amounts of energy. · 太阳把氢原子核聚变成氦,释放巨大量的能量。
Mass into energy, and balancing
- In both fission and fusion, a tiny amount of mass is lost and turned into energy.
- In any nuclear equation, the top numbers (nucleon numbers) balance, and so do the bottom numbers (proton numbers).
- That lets you find a missing number — for example, how many neutrons are released.
Nuclear fission of a U-235 nucleus
质量变能量,以及平衡
- 在裂变和聚变两者中,极少量的质量损失并转变成能量。
- 在任何核方程中,顶部数字(核子数)平衡,底部数字(质子数)也平衡。
- 那让你找出一个缺失的数字——例如,释放多少个中子。

一个 U-235 原子核的核裂变
In $^{235}_{\ 92}\text{U} + {}^{1}_{0}\text{n} \rightarrow {}^{141}_{\ 56}\text{Ba} + {}^{92}_{36}\text{Kr} + x\,{}^{1}_{0}\text{n}$, how many neutrons $x$ are released? · 在 $^{235}_{\ 92}\text{U} + {}^{1}_{0}\text{n} \rightarrow {}^{141}_{\ 56}\text{Ba} + {}^{92}_{36}\text{Kr} + x\,{}^{1}_{0}\text{n}$ 中,释放多少个中子 $x$?
Nucleon numbers must balance: $235 + 1 = 141 + 92 + x$, so $236 = 233 + x$ and $x = 3$. · 核子数必须平衡:$235 + 1 = 141 + 92 + x$,所以 $236 = 233 + x$ 且 $x = 3$。
In fission and fusion, a small amount of mass is turned into energy. · 在裂变和聚变中,极少量的质量被转变成能量。
Both processes lose a tiny amount of mass, which is released as a large amount of energy. · 两个过程都损失极少量的质量,它作为大量的能量被释放。
You've got it
- fission: a heavy nucleus splits → two smaller nuclei + neutrons + energy (chain reaction)
- fusion: two light nuclei join → a heavier nucleus + energy (powers the Sun)
- both convert a little mass into energy
- nuclear equations balance top (nucleon) and bottom (proton) numbers
你掌握了
- 裂变:一个重原子核分裂 → 两个更小的原子核 + 中子 + 能量(链式反应)
- 聚变:两个轻原子核结合 → 一个更重的原子核 + 能量(为太阳提供动力)
- 两者都把一点质量转变成能量
- 核方程平衡顶部(核子)和底部(质子)数字