$\mathrm{CaO}$ and ${\mathrm{CO}}_2$ are produced by heating ${\mathrm{CaCO}}_3$. What is the type of the reaction and the process?

When ferrous sulphate is heated the following reaction takes place:

$2{\mathrm{FeSO}}_4\left(\mathrm{s}\right)\to {\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)+{\mathrm{SO}}_2\left(\mathrm{g}\right)+{\mathrm{SO}}_3\left(\mathrm{g}\right)$

The above reaction is called _____of ferrous sulphate.

Make a crossword puzzle and solve it with the help of following clues.

ACROSS
2. An example of a decomposition reaction.

4. In a chemical reaction atoms are.

6. Another name for a combination reaction.

8. Energy is transferred from the surroundings to the reactants in this type of reaction.

9. Substances that takes oxygen.

10. An example of an exothermic reaction.

DOWN

1. An example of an endothermic reaction.

3. A chemical equation is balanced by changing or adding _____.

5. In this reaction energy is transferred from the reactant to the surroundings.

7. When a chemical reaction and its reverse reaction are occurring at the same time and at the same rate.