Why is photosynthesis a chemical reaction?
a because new substances are formed
b. because an input of energy is required
c. because the reactants are compounds
d. because the products include an element

A.

Explanation: A chemical reaction is a chemical change that occurs when two or more substances combine to form a new substance . Photosynthesis turns carbon dioxide and water into oxygen and carbohydrates, therefore a chemical change occurs.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.