Ineed on 5,6,7. i would give you guys a you. this is going to be due very soon.

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!

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.