Answer:
5) Plant; 6) Heat; 7) never heard of chemosynthesis, sorry :(
Explanation:
A plant is the only thing in an ecosystem that uses photosyenthesis. This includes trees, algea, and grass.
80% of energy is lost as heat used in order to keep the animal warm.
I am really sorry I couldn’t help with 7!
The two elements that produce background radiation on earth are Radon and Uranium. Airborne radon can decay on its own. Radon undergoes alpha decay to produce Polonium. Uranium naturally undergoes alpha decay to produce Thorium.
B.
And maybe put your question in the English/Literature tag next time lol