Nwhich two types of reactions do opposite chemical changes occur? double replacement and combustion single replacement and double replacement synthesis and decomposition combustion and synthesis

synthesis and decomposition

Explanation:

1. Double displacement reaction is one in which exchange of ions take place.

Example:

2. Combustion is a type of chemical reaction in which fuel is reacted with oxygen to form carbon dioxide and water.

Example:  

3. Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.

Example:

4. Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.

Example:

5. Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.

Example:

Thus synthesis ad decomposition are opposite chemical changes.

b.a device that inputs heat into a cool object

the ima (higher than 1m) will be greater than the ima with the height of 1m.