十万个为什么·科学启蒙30篇（3）

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火焰为什么通常是橙色的

An orange flame appears when tiny hot particles of carbon—called soot—glow in the heat like tiny lightbulbs.
This type of incandescence happens in incomplete combustion, where fuel doesn’t burn fully due to limited oxygen.
Candles, wood fires, and gas stoves on low settings all produce such warm-colored flames.
Blue flames, in contrast, come from complete combustion and emit light mostly from excited gas molecules.
The temperature of an orange flame ranges from about 1,000°C to 1,200°C—hot, but cooler than blue ones.
Sodium in salt or food splatters adds a stronger yellow-orange hue because sodium atoms glow brightly at that wavelength.
A candle’s wick draws melted wax upward, where capillary action feeds vaporized fuel into the flame zone.
If you restrict airflow to a Bunsen burner, its blue flame turns orange and flickers more wildly.
Firefighters watch flame color carefully: orange suggests smoldering materials, while blue hints at gas leaks.
Even the Sun’s visible surface glows orange-yellow—not from soot, but because its 5,500°C surface emits peak light in that range.

听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。

Candles, wood fires, and gas stoves on low settings all produce such warm-colored flames. 蜡烛、木火以及调至低档的燃气灶都会产生这类暖色调火焰。
Firefighters watch flame color carefully: orange suggests smoldering materials, while blue hints at gas leaks. 消防员密切观察火焰颜色：橙色提示阴燃物质，蓝色则可能暗示燃气泄漏。
Blue flames, in contrast, come from complete combustion and emit light mostly from excited gas molecules. 相比之下，蓝色火焰源于完全燃烧，其发光主要来自受激气体分子。

这篇中文题目最接近哪一句？火焰为什么通常是橙色的一次学校运动会的通知一份超市购物清单

课文第一句的意思更接近？微小的炽热碳颗粒（即烟灰）在高温下发光，如同无数微型灯泡，形成橙色火焰。今天学校放假了。请把窗户打开。

这一课主要在讲什么？（看英文标题） Why Is Flame Usually Orange? How to cook noodles A maths worksheet

Candles, wood fires, and gas stoves on low settings all produce such warm-colored flames.

Candles, wood fires, and gas stoves on low settings all produce such warm-colored flames.

第一版：录下来、回听、再听标准音。系统打分以后再加。

用今天的表达，自己说一句。

例子：Candles, wood fires, and gas stoves on low settings all produce such warm-colored flames.