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.
Best Answer: aluminium is a metal because 1. it has the ability to donate 3 electrons & as per the definition of metals, metals are substances which donate valence electrons 2. it has lustre 3. it is malleable i.e. drawn into sheets & ductile i.e. elongated into wires 4. it is a solid at room temperature 5.luminium is a metal, because it's hard, form a positive ion, an electric and heat conductor ,have a high melting point and have a shiny silver coloured.