B is the answer. For an equation to be balanced there must be the same amount of each element on the two sides. The only one where this is the case is B.
Answer is: <span>excited state.
In </span>excited state, hydrogen has<span> higher </span>energy<span> than in the </span>ground state (state with lowest energy). H<span>ydrogen atom has one </span>electron<span> in the lowest possible </span>orbit<span> (1s), when atom absorbs</span><span> energy</span><span>, the electron move into an excited state (quantum numbers greater than the minimum possible). </span>Electron lifetime in excited state is short.
The correct answer is:
3) Earthquakes can be caused by volcanic eruptions.
You were right :)