Lesson 5: Corrosion of metals

How we can protect metals from rusting?

• by making alloys

• by putting it into water

• by polishing it

• by cutting into small pieces

How do people produce metals?

• We can get them by smelting ores

• We can get them from minerals

• We can get them from microorganisms

Metal + ...... = Metal Oxide + Hydrogen Gas

• Water steam

• Hydrochloric acid

• Cold Water

• Nitric Acid

Which metals reacts fast even with cold water to produce hydrogen gas and metal hydroxide?

• calcium

• strontium

• barium

• chlorine

By smelting metals from ores, we turn them from a.... state to .....

(a)  

Metals chemically interact with water, oxygen, microorganisms, etc. We call this process (a)  

Some metals like iron or zinc do not react with cold and hot water, but they can react with water steam at high temperatures. For example, Iron (Fe) + Water Steam (H2O) = (a)  

Only metals like gold and platinum, sometimes silver and copper can be found on the Earth in free metallic form.

These metals:

• are not active

• generally do not produce compounds in nature, but all other metals exist in nature in forms of compounds.

• have silvery-blue color