Video Transcript
What do you observe on burning
magnesium in air? (A) A liquid is formed. (B) A white powder is formed. (C) A gas evolves. (D) A solid that is bendable and
bright is formed.
Since this question is asking us to
identify what is observed when magnesium is burned in the air, let us first discuss
what occurs in this chemical reaction.
In any chemical reaction, chemicals
that start the chemical reaction are called reactants. And chemicals that are formed
during the chemical reaction are called products. Reactants are separated from the
products with an arrow, which means “reacts to produce.”
In this question, one of the
reactants is magnesium, which is burned. Magnesium is a silver metal usually
found as a ribbon, since it is malleable. In order for a chemical reaction to
occur, magnesium must react with something in the air, but what? The magnesium reacts with the
oxygen gas in the air when the magnesium is burned. When this chemical reaction occurs,
magnesium oxide is formed as the product. When this chemical reaction occurs,
the silver ribbon begins to change into a white powder substance. Eventually, all of the magnesium
ribbon will react with the oxygen in the air and only the white powder remains. This white powder is the product,
magnesium oxide.
Now that we have discussed this
chemical reaction, let us take a look at our answer choices. We can see that answer choice (B)
matches the description of the product, magnesium oxide. Therefore, a white powder is formed
when observing the burning magnesium in air.
