A compound X has a molecular ion peak in its mass spectrum at m/z 136. What information does this tell us about X

In 1901, thomas edison invented the nickel-iron battery. the following reaction takes place in the battery. fe(s) + 2 nio(oh)(s) + 2 h2o(l) fe(oh)2(s) + 2 ni(oh)2(aq) how many mole of fe(oh)2, is produced when 5.35 mol fe and 7.65 mol nio(oh) react?

What happens to isotopes that are unstable?

Write the overall equation for the reaction occurring in lithium battery?