This is an acid base reaction which is basically a double displacement reaction. However, since carbonic acid is produced, it rapidly decomposes to carbon dioxide and water.
Answer:
(c)-He separates the larger pebbles and other debris from the finer sand by sifting it with wire mesh.
Explanation:
A mixture is an association of substances that not react between them. It can be homogeneous when it's not possible to see the substances, or heterogeneous when it's possible to see each the substances.
Randy separates the substances of the soil with a wire mesh, so it's possible to define the substances, then the mixture is heterogeneous.
If an unknown substance CANNOT be broken down into simpler substances, it is AN ELEMENT made of one kind of atom.
