Initially, an electron is in the n= 3 state of hydrogen. if this electron acquires an additional1.23 ev of energy, what is the value of n in the final state of the electron?

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?