Properties of Photons · 光子的性质
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| photons/ˈfəʊtɒnz/ | 光子 | guāng zi |
| Planck's constant/plæŋks ˈkɒnstənt/ | 普朗克常数 | pǔ lǎng kè cháng shù |
Light comes in packets
- Light is not a smooth stream -- it arrives in tiny bundles.
- Each bundle carries a fixed, exact amount of energy.
- Bluer light packs more punch per bundle than red.
- These packets explain how light and atoms trade energy.
光以小包的形式到来
- 光不是平滑的流——它以微小的小包到来。
- 每个小包携带固定、精确的能量。
- 越蓝的光,每个小包的冲力越大,超过红光。
- 这些小包解释了光与原子如何交换能量。
Each photon's energy
- Light comes in packets called photons 光子.
- A photon's energy depends only on its frequency:
- Here $h$ is Planck's constant 普朗克常数.
每个光子的能量
- 光以称为光子的小包到来。
- 光子的能量只取决于它的频率:
- 这里 $h$ 是普朗克常数。
In $E = h\nu$, the symbol $h$ is called ____ constant. · 在$E = h\nu$中，符号$h$被称为____常数。
$h$ is Planck's constant, $6.63\times10^{-34}\ \text{J·s}$. · $h$是普朗克常数，$6.63\times10^{-34}\ \text{J·s}$。
Higher frequency, more energy
- A higher-frequency photon carries more energy.
- Shorter wavelength means higher frequency means more energetic.
- A UV photon beats a red one, packet for packet.
频率越高,能量越大
- 频率更高的光子携带更多能量。
- 波长更短意味着频率更高,意味着能量更大。
- 紫外光子逐包胜过红光光子。
A photon's energy is set by its... · 光子的能量由其...决定
$E = h\nu$ -- energy depends on frequency, not brightness. · $E = h\nu$——能量取决于频率，而非亮度。
A shorter-wavelength photon carries more energy than a longer-wavelength one. · 波长较短的光子比波长较长的光子携带更多能量。
Shorter wavelength means higher frequency and higher energy. · 波长越短意味着频率越高且能量越大。
Matching photons to jumps
- An electron jumps levels only if a photon's energy fits the gap exactly.
- The photon is absorbed and the electron climbs.
- Emitting a photon drops it back down.
让光子匹配跃迁
- 只有当光子能量恰好符合能级间隔时,电子才跃迁。
- 光子被吸收,电子向上爬。
- 发射一个光子则让它落回。
A photon's energy · 光子的能量
Photon energy is proportional to frequency: bluer, higher-frequency light carries more energy per photon. · 光子能量与频率成正比：蓝色、高频光携带的光子能量更高。
An electron absorbs a photon only if the photon's energy matches the level gap. · 只有当光子能量匹配能级差时，电子才会吸收光子。
Energy levels are quantized, so only an exact match is absorbed. · 能级是量子化的，因此只有精确匹配才能被吸收。
Find the energy of a photon of frequency $5\times10^{14}\ \text{Hz}$ (with $h = 6.63\times10^{-34}$).
- $E = h\nu = (6.63\times10^{-34})(5\times10^{14})$.
- $E \approx 3.3\times10^{-19}\ \text{J}$.
求频率为 $5\times10^{14}\ \text{Hz}$ 的光子的能量(取 $h = 6.63\times10^{-34}$)。
- $E = h\nu = (6.63\times10^{-34})(5\times10^{14})$。
- $E \approx 3.3\times10^{-19}\ \text{J}$。
A photon has $\nu = 2\times10^{15}\ \text{Hz}$ and $h = 6.63\times10^{-34}$. Its energy? Enter the coefficient before $\times10^{-18}$ J (2 decimals). · 光子具有$\nu = 2\times10^{15}\ \text{Hz}$和$h = 6.63\times10^{-34}$。其能量是多少？请输入$\times10^{-18}$ J前面的系数（保留2位小数）。
$E = h\nu = (6.63\times10^{-34})(2\times10^{15}) = 1.33\times10^{-18}\ \text{J}$.
A dim blue light versus a bright red light. Which has higher-energy photons? · 微弱的蓝光与明亮的红光相比。哪种光的光子能量更高？
Blue's higher frequency wins; brightness is just the number of photons. · 蓝色的高频占优势；亮度仅仅是光子的数量。
A photon's energy depends on frequency (or wavelength), not on brightness -- a dim blue light still has higher-energy photons than a bright red one. Use $E = h\nu$ with frequency or $E = hc/\lambda$ with wavelength, and do not mix them. Energy comes in fixed packets, so only an exactly-matching photon causes a jump.
光子的能量取决于频率(或波长),而不是亮度——暗淡的蓝光,其光子能量仍高于明亮的红光。用 $E = h\nu$ 配频率,或 $E = hc/\lambda$ 配波长,别混用。能量以固定小包出现,所以只有恰好匹配的光子才引起跃迁。
Light travels as photons, each carrying $E = h\nu = hc/\lambda$, where $h$ is Planck's constant. Higher frequency (shorter wavelength) means a more energetic photon, set by frequency, not brightness. An electron absorbs a photon only when its energy exactly matches the level gap.
光以光子的形式传播,每个携带 $E = h\nu = hc/\lambda$,其中 $h$ 是普朗克常数。频率更高(波长更短)意味着光子更有能量,由频率而非亮度决定。只有当光子能量恰好符合能级间隔时,电子才吸收它。