bubble; air bubble
Typically refers to bubbles in a liquid, but can also be used for gas pockets in solids or other media. Common in scientific and everyday descriptions.
Many small bubbles can be seen in the water.
This glass contains air bubbles.
A small bubble had formed inside the glass.
A bubble got trapped in the adhesive.
This concrete contains a lot of air bubbles.
After a while, the bubbles disappeared.
水泡 looks similar and can mean a bubble of water, but it is mostly used figuratively (as in 水泡に帰す, 'to come to nothing'), unlike the literal, physical 気泡.
counter for small objects; counter for pieces · counter for military units · individual; one person · counter for years of age difference; counter for school years
Compound of 気 (gas, air) and 泡 (bubble). The reading is on'yomi for both characters.