(chemistry) a chemical reaction

(inorganic chemistry) a noble gas

(Internet slang) Clipping of 気がする (ki ga suru).

participation, commitment

to participate, to join, to enter

to know, be aware of / to learn, acquire, / to be acquainted with, to know (someone) / (colloquial, in the negative) to care in the least about, to be concerned with,

chemistry (branch of natural science)

to react chemically / to respond, to react / be responsive, be sensitive

chemical reaction / reaction, response / feedback

natural gas / gas / a dense thick fog