Please elaborate more on your question so I can help you
The answer is a
the equation needs to be balanced. There are fewer oxygen atoms in the equation than hydrogen or a carbon
A) gases particles are far apart
The reason why the snails are dead because the snails lack oxygen for it is a model of closed ecosystem. Another reason to this is that they lack abiotic factors that they need in surviving or as they live for the place that they are living lacks a lot and are not enough for them to last or survive. Lastly, the water could have not been a contributor for them to live for they may not be able to live in a water environment and could only dwell in land.
Energy in a machine can be something technical like a wire or something went wrong with the system
