Answer:
C the number and placement of the electrons
Explanation:
Elements react with one another because they want to achieve a full valence shell of electrons. The noble gases already have a full valence shell of electrons, so they are unlikely to react with other elements.
By adding the enthalpies of the intermediate reactions together to get the enthalpy of the desired reaction
During a phenomenon called beta decay the neutron of the isotope uranium 237 emits/releases an electron causing an increase of atomic number. With the reference of a periodic table the "new" element is Neptunium or Np-237.
To find the mass you need to find the weight of a mol of the molecules by adding up the atomic mass.
N = 14.007 g/mol
H = 1.008 g/mol
S = 32.065 g/mol
O = 16 g/mol
2(14.007) + 8(1.008) + 32.065 + 4(16) = 132.143 g/mol
Now you know how much an entire mol weight you multiply it by how much you actually have
0.00456 * 132.143 = 0.603 g