Can someone help me with these please?

1) Use water as an example to contrast the properties of a compound with the elements from which it is composed.

2) If you tried to breath carbon dioxide, you would suffocate. Why, then, is carbon dioxide essential to all life on Earth?

We shall be happy to critique your thoughts. Hint: Look up the properties of oxygen and hydrogen and contrast those properties with those of water.

2. Hint: Plants need CO2 for photosynthesis.

Oh, thanks. I already have the first one. And I think your hint for the second should be sufficient enough.