A test tube is a thin glass tube used to hold small samples. Fill a test tube.
The round bottom means it must stand in a rack, which is why racks exist. A test tube is heated at an angle and pointed away from everybody, which is the first rule anybody learns.
1nountest tubeA thin glass tube used to hold small samples.
“The test tube cracked as soon as it hit cold water.”
test tube is equipment.
Practised in Chemistry & Elements