How the character is built
The 气 radical marks this as a gas, and that is not a coincidence of this one character — it holds right across the table. Read the radical first and the element's state at room temperature is already settled.
Where you actually meet it
氯气 (lǜqì) chlorine gas
The element itself
Chlorine is a heavy green-yellow gas that no one meets in its elemental form by choice, and it exists in nature only as chloride, mostly dissolved in the ocean or crystallised in salt beds. Splitting it back out takes electricity: brine electrolysis produces chlorine at one electrode and sodium hydroxide at the other, so the two are made in fixed proportion whether the market wants that ratio or not — an awkwardness that has shaped the chemical industry for a century.
Where it sits among the 118
First isolated in 1774.
In living things
Chloride is the most abundant negative ion outside cells, and mostly it follows sodium around as ballast — but it has three jobs of its own. The stomach's parietal cells pump out hydrogen ions and let chloride follow, producing hydrochloric acid strong enough to sit near pH 1, kept off the stomach's own wall by a layer of mucus. In red blood cells, chloride swaps in and out across the membrane as carbon dioxide is converted to bicarbonate for the journey to the lungs. And in the brain, fast inhibition is literally chloride: the receptors that quieten a neuron on a millisecond timescale do it by opening a chloride channel.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
氯Chlorine in the dictionary →Others built the same way
Every one of these carries 气, and every one is a gas.