为什么氢气那么难储存？
Why is hydrogen so hard to store?
氢气很轻，常温常压下体积能量密度极低；要么高压压缩、要么极低温液化，都耗能且有安全风险。
Hydrogen is very light with low volumetric energy density at room conditions; storing it needs high pressure or cryogenic liquefaction—both energy-hungry and risky.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#储氢 #能量密度 #压缩
为什么医院氧气来自空气而非化工厂？
Why does hospital oxygen come from air rather than a chemical plant?
把空气液化后再分馏，利用氮（-196°C）与氧（-183°C）沸点不同，把氧气和氮气分开，得到高纯氧气供医疗和工业。
Liquefied air is fractionally distilled; N2 (-196 C) and O2 (-183 C) boil off at different temperatures, yielding pure oxygen for medical/industrial use.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#空气分馏 #液化 #制氧
为什么液氨能用来制冷？
Why can liquid ammonia be used for refrigeration?
液氨汽化时要吸收大量热，工业制冷常利用它蒸发吸热来降温，是一种古老的制冷剂。
Liquid ammonia absorbs a lot of heat as it vaporizes, so its evaporation is used to chill things in industrial refrigeration.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#氨 #制冷 #蒸发
化学实验为什么要在通风橱里操作有毒气体？
Why use a fume hood for toxic gases in labs?
通风橱把有害蒸气吸走并排到室外，避免实验者吸入中毒。
A fume hood draws hazardous vapors away and vents them outside, protecting the user from inhalation.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#实验室 #通风 #安全
为什么气球过几天就瘪了？
Why does a balloon go soft after a few days?
气球里的气体分子很小，会从橡皮上肉眼看不见的小缝里慢慢溜走。
The gas molecules inside are tiny and slowly slip out through invisible gaps in the rubber.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#气球 #漏气 #气体
为什么吹出来的泡泡都是圆圆的？
Why are soap bubbles always round?
泡泡表面想缩到最小，而同样大小里圆球的表面积最小，所以自然变成圆球。泡泡水里还有一层薄薄的表面张力皮肤，把它拉成最省能量的形状，也就是圆形。
A bubble's skin wants to be as small as possible, and a round shape has the least surface, so it becomes a ball. The surface tension of the soapy film pulls it into the shape that uses the least energy, which is a sphere.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#泡泡 #形状 #表面
为什么玉米粒放进锅里会噼啪变成爆米花？
Why does a corn kernel pop into popcorn?
玉米粒里有一点点水，加热后水变成蒸汽把外皮撑破，就砰地开花啦。
A kernel has a little water that turns to steam and bursts the shell with a pop.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#爆米花 #蒸汽 #加热
为什么老远就能闻到妈妈做的饭香？
Why can we smell yummy food from far away?
香味是一群小气味分子，它们会自己飘到鼻子里告诉我们。
Smells are tiny molecules that float through the air all the way to our nose.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#气味 #分子 #空气
实验室里闻气味为什么不能把鼻子凑到瓶口直接闻？
Why shouldn't you sniff chemicals directly in a lab?
直接吸入可能中毒或刺激，正确做法用手在瓶口轻扇，让少量气体飘过来闻。
Direct inhalation can poison or irritate; instead waft vapor toward your nose with your hand.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#实验室 #闻气味 #安全
为什么浴球丢进水里会滋滋冒泡？
Why does a bath bomb fizz in water?
浴球里的酸和碱碰到水会打架，放出二氧化碳小气泡，所以滋滋响。酸和碱碰到一起就会发生化学反应，气泡冒完浴球就化掉了。
The acid and base inside a bath bomb meet water and release carbon dioxide bubbles, making it fizz. When acid and base react they bubble away, and the bath bomb slowly dissolves.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#浴球 #气泡 #酸碱
为什么烧开水时会冒出白白的蒸汽？
Why does boiling water make white steam?
水受热变成看不见的水蒸气，遇冷又凝成许多小水珠，看起来像白烟。我们看到的白烟并不是气体本身，而是水蒸气遇冷变成的无数小水滴。
Hot water turns into invisible vapor that cools and forms tiny water drops we see as steam. The white steam is not the gas itself but countless tiny droplets made when the vapor meets cooler air.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#水蒸气 #沸腾 #气体
空气看不见摸不着,怎么知道它真的存在?
Air is invisible — how do we know it is really there?
吹一吹气球,鼓起来的就是被你抓住的空气!挥挥手感觉到的微风、树叶摇曳、风筝飞上天,都是空气在工作。它就围绕在我们身边,虽然眼睛看不见,皮肤却能感觉到它。
Blow a balloon — the puff you catch IS air! Wave your hand to feel a breeze; leaves sway and kites fly because air pushes. It surrounds us all the time: invisible to eyes but easy for skin to feel.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版化学分册,少年儿童出版社,2013
Ten Thousand Whys: Chemistry volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#空气 #风 #感知
为什么加了泡打粉的蛋糕会鼓起来？
Why does cake rise with baking powder?
泡打粉遇到水和小热会放出二氧化碳小气泡，把面糊顶得胖胖的。泡打粉里本来就有酸和碱，一碰到水和热就开始冒泡，蛋糕就蓬松了。
Baking powder releases carbon dioxide bubbles in heat and water, puffing the batter up. It already contains acid and base, so it starts bubbling as soon as it meets water and warmth.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#泡打粉 #膨胀 #气体
为什么打开汽水会咕噜咕噜冒泡泡？
Why does soda fizz and bubble when opened?
汽水里面藏了许多二氧化碳小气泡，盖子一开它们就跑出来啦。
Soda hides tiny bubbles of gas called carbon dioxide that escape when the bottle opens.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#汽水 #气泡 #气体