The isotope of an atom contains 40 protons and 51 neutrons that only has two neutrons added to it. what isotope is created a) zirconium-30b) antimony-53c) zirconium-93d) antimony-93

Well, the isotope has the same atomic# as the atom, so it must be Zirconium still. When you add together all the neutrons and protons (that have negligibly similar mass), you'll find that the answer is Zirconium 93

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g