If an isotope of an element has 40 neutrons and a mass number of 79, how many electrons must it have?

Use the bond energies provided to estimate δh°rxn for the reaction below. ch3oh(l) + 2 o2(g) → co2(g) + 2 h2o(g) δh°rxn = ? bond bond energy (kj/mol) c-h 414 c-o 360 c=o 799 o=o 498 o-h 464 use the bond energies provided to estimate δh°rxn for the reaction below. ch3oh(l) + 2 o2(g) → co2(g) + 2 h2o(g) δh°rxn = ? bond bond energy (kj/mol) c-h 414 c-o 360 c=o 799 o=o 498 o-h 464 +473 kj +206 kj -392 kj -91 kj -486 kj