Browse Lemmas
10 lemmas found
acid
a chemical substance with a pH below 7 that can dissolve metals and turn litmus paper red.
base
a chemical substance with a pH above 7 that can neutralize acids and turn litmus paper blue.
ammonia
A pungent, colorless gas (NH₃) composed of nitrogen and hydrogen, widely used in fertilizers, cleaning products, and industrial chemistry.
chlorine
A chemical element (symbol Cl) that is a yellow-green, toxic gas with a pungent smell, commonly used to disinfect water and in manufacturing.
hydrogen
The lightest and most abundant chemical element (symbol H), a colorless, odorless gas that combines with oxygen to form water.
methane
A colorless, odorless, flammable gas (CH₄) that is the main component of natural gas and a significant greenhouse gas.
nitrogen
A chemical element (symbol N) that is a colorless, odorless gas making up about 78% of Earth's atmosphere, essential for plant growth.
carbon dioxide
A colorless gas (CO₂) produced by burning carbon and organic compounds and by respiration, absorbed by plants in photosynthesis.
oxygen
A chemical element (symbol O) essential for respiration, making up about 21% of Earth's atmosphere.
lithium
A soft, silvery-white chemical element (symbol Li), the lightest metal, used in batteries and psychiatric medication.