nitrogen
nitrogen — noun
1. a gas that makes up the largest part of the air around Earth and is an important
a gas that makes up the largest part of the air around Earth and is an important building block of all living plants and animals; it has no colour, taste, or smell.
Farmers add nitrogen to the soil to help their crops grow better each season.
collocation: add nitrogen to the soil
The air we breathe contains about 78 percent nitrogen and 21 percent oxygen.
collocation: nitrogen + oxygen / 78 percent of air
When Emily's science class tested the gas, they found it was mostly nitrogen.
Liquid nitrogen is cold enough to freeze food very quickly during shipping.
Plants need nitrogen from the soil to make the proteins they require to grow.
- N
chemical symbol used on the periodic table and in formulas; not used in ordinary speech or writing
文法句型
uncountable: nitrogen + verb (singular)
用法筆記
Nitrogen is an uncountable noun — you cannot say 'a nitrogen' or 'many nitrogens'. It is typically used in scientific, agricultural, or environmental contexts rather than in everyday conversation about air.