6. what mechanisms or events are needed for a star to make heavier elements than iron?

The nucleosynthesis mechanism is responsible for a star to make elements heavier than iron.

Explanation:

Through the process of fusion or nucleosynthesis in stars, the heavier elements are formed by the fusion of lighter elements. In this process an extensive amount of temperature is needed to make super- fast collisions.

By this process, heavier elements like iron are formed in our stars with ten times more use of matters. Elements like iron formation demands excessive energy. By the Supernova explosions iron is formed.  

Equation:  29 + a = 56

Your friend gathers 27 apples.

Step-by-step explanation:

29 + a = 56            Isolate the variable by subtracting both sides by 29

        a = 27

Your friend gathers 27 apples