This painless condition occurs when the little bumps on your tongue grow long and trap bacteria that live in your mouth -- making the tongue look black and hairy. Causes can include antibiotic use, poor oral hygiene, smoking, drinking a lot of tea or coffee, and not producing enough saliva.
Hello, Jie. The word passivate is a bit troublesome because aluminum cannot be passivated in the same sense as stainless steel; but it can be passivated in the same sense as zinc plating, i.e., with a chromate conversion coating.
Report Abuse. Aluminum is a good conductor of electricity. A common material that isn't conductive is glass but glass will conduct heat. Wood isn't heat conductive or an electricity conductor but has a low combustion point.eport Abuse. Aluminum is a good conductor of electricity. A common material that isn't conductive is glass but glass will conduct heat. Wood isn't heat conductive or an electricity conductor but has a low combustion point.