john bunsenburner wrote:2. My teacher drops sodium into water, he says its reactive and forms h2 gas and an alkaline solution(no word about sodium hydroxide...).
Sodium hydroxide would be that alkaline solution. Sometimes it's better not to be too specific in the earlier school years.
The point of the alkali metals/water experiment is to show their reactivity, and demonstrate that not all things are equally reactive in a visual manner.
Tell a student that hydrogen gas and an alkali are formed when an alkali metal reacts with water, they'll likely remember it.
Tell them that hydrogen gas and sodium hydroxide is formed if you drop in sodium, and other hydroxides with the other alkali metals... they'll probably forget it, and forget that sodium hydroxide is even an alkali...
Next he grabs some copper and drops it in. He askes what happened to the copper, i say, "Nothing copper is unreactive".
He says, "Rubbish! The copper gets wet!"
Actually, that's only half true. Copper doesn't get wet in the same way as something such as your hands.
In fact, it's not entirely true to say that copper gets wet at all.