1
a chemical used in [process]
used in 是过去分词短语作后置定语，相当于 that is used in。
A chemical used in this test must be colorless.
用于这项试验的化学品必须是无色的。
化学品；化学物质
先理解核心含义，再看它在真实句子里的用法。
化学品；化学物质
a substance that is used in or produced by a chemical process, such as an element or compound
A chemical used in this test must be colorless.
用于这项试验的化学品必须是无色的。
Any specific chemical element or chemical compound or alloy.
由原子或分子变化反应产生或使用的物质
material produced by or used in a reaction involving changes in atoms or molecules
The lab stores many chemicals in glass bottles.
实验室在玻璃瓶中储存许多化学品。
This chemical is dangerous if you touch it.
这种化学品如果接触会有危险。
They use chemicals to make plastic.
他们使用化学品来制造塑料。
used in 是过去分词短语作后置定语，相当于 that is used in。
A chemical used in this test must be colorless.
用于这项试验的化学品必须是无色的。
with 短语修饰 chemical，表示该化学品具有的特征。
A chemical with a strong smell should be handled carefully.
有强烈气味的化学品应小心处理。
that 引导定语从句限定 chemical；在口语中 that 有时可省略。
Chemicals that are flammable must be labeled.
易燃的化学品必须贴上标签。
Not this
The lab stores many chemical.
Use this
The lab stores many chemicals.
chemical 作名词时是可数名词，指一种化学品；前面有 many 时要用复数形式 chemicals。中文“化学物质”没有单复数变化，容易漏掉 -s。
Not this
I am studying chemical at university.
Use this
I am studying chemistry at university.
表示学科“化学”用 chemistry，而 chemical 作名词指“化学品/化学物质”；把中文的“化学”直接套成 chemical 是词性/词义误用。学习或研究某学科要用 study + 学科名称。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
有毒化学品
The factory released toxic chemicals into the river.
那家工厂向河里排放了有毒化学品。
工业化学品
Workers at the plant handle many industrial chemicals every day.
工厂的工人每天处理许多工业化学品。
家用化学品
Keep household chemicals out of the reach of children.
把家用化学品放在儿童够不到的地方。
农用化学品
Farmers use agricultural chemicals to protect their crops from pests.
农民使用农用化学品来保护庄稼免受虫害。
危险化学品
Trucks carrying hazardous chemicals must follow special safety rules.
运载危险化学品的卡车必须遵守特殊的安全规定。
化学物质X（美国动画《飞天小女警》中赋予主角超能力的物质）
In the cartoon 'The Powerpuff Girls', Chemical X is the accidental ingredient that brought the three heroines to life.
在动画片《飞天小女警》中，化学物质X是一种偶然加入的成分，让三位主角获得了生命。
用化学物质创造更好的生活。
The saying 'Better living through chemicals' is often used as a humorous reminder of how much our lives depend on synthetic products.
“用化学物质创造更好的生活”这句话常被用来幽默地提醒人们：我们的生活有多依赖合成产品。
Use chemical naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
chemical与chemistry同以chem开头，化学课实验瓶里装的都是chemical(化学品)。
语域：neutral 常见场景：实验室、工业生产、日常环保话题 该词在科技、工业和日常语境中均为中性，正式和非正式场合都适用；通常指参与化学反应的物质或化工产品。
这些词都与 chemical 一样以 -ical 结尾；本列表中 -ical 读作 /ɪkəl/。但它们重读音节中的元音和其后的辅音与 chemical 不同，因此并不与 chemical 真正押韵。political 的重音在第二音节，读音尤其容易按拼写想错。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.