they are so you can see what amount of juice or something you have in it
Science test tubes; generally made of pyrex to reduce breakage, are tubual containers often used in experiments. They can be heated, and cooled, and can you can use liquid or powder substances in them.
Test tube racks are commonplace in school science labs and are used routinely to securely hold test tubes or boiling tubes that are being observed or filled.
Test tubes are most often used in professional science and medical experiments to hold samples of substances. They are also frequently seen in school science classes and hospitals.
brush
Test tube racks are used to support the test tubes but unlike the test tube holder, it can store the test tubes without anyone who will hold the rack... hope this helps!
Science test tubes may go anywhere from 2 dollars for a pack to 100 plus dollars for a single tube. It varies on the type of test tube you are looking to buy.
You can purchase test tubes from a science equipment magazine. They will be available in any good stores. Also you can go onto eBay to buy some test tubes.
Indigo Instruments offers a variety of science equipment, including test tubes, at its website, Indigo.com. Standard chemistry lab test tubes are 70 cents apiece.
burettes, flasks, chemicals
Well when you are doing scientific experiments with test tubes you may put different substances or whatever you're using in different tubes therefore to separate them and study them individually... Does that help you at all?
They are called: - Test tubes - Cultural tubes - Sample tubes
They are used to clean test tubes. :)