What two factors contribute to the formation of deep sea currents?

Is this a single replacement reaction or there is no

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?

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?