What term best describes the type of reaction that happens when a single element reacts with a molecule or compound, producing a new single element and a new molecule or compound? a. an isolation reaction b. a single combustion reaction c. a single replacement reaction d. a double replacement reaction

a single replacement reaction

Explanation:

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

Example:  

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

Example:

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

Example:

Here Zinc an element reacts with the compound copper chloride  to form new compound zinc chloride and new element copper.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.