The atomic number of an element gives the proton and electron in the atom while the mass number gives the total number of protons and neutron
For the answer to the question above, <span>17.9 x 1.74 gram Mg = 31.15 gram Mg = (31.15/24.31) = 1.28 mole Mg </span>
<span>2 Mg + O2 ---> 2MgO </span>
<span>so 1.28 mole Mg reacts with 0.641 mole O2
I hope my answer helped you. Feel free to ask more questions. Have a nice day!</span>
<span>The expected results of the Rutherford's gold foil experiment were that the relative massive alpha particles (respect to electrons) could go through the gold foil without being deviated of their trajectory or only small deviations due to the uniformly distributed positive charge of the protons. The real results showed that some particles were significantly deviated of the trajectory (large deviation angles and even some particles bounced back to the source). This lead Rutherford to reject the plum pudding model and propose a new one. The new model proposed by Rutherford was that the atom consisted of a small and every dense nucleus (which contained the positive charge, protons) and a vast region, almost empty, but where the electrons were, surrounding the nucleus.</span><span />
It could be because something much larger that we have yet to discover is pulling objects to it like a black hole of something else that we can't see with the human eye.
