Sublevel 2s and 2p contains the valence electrons for nitrogen.
Answer
Calculating the mass number for an atom requires that we know the atomic number and the number of protons in the atom’s nucleus. The mass number then gives us the average weight of atoms of a given element. However, as long as the number of protons equals the number of neutrons, the values balance out and we always obtain a whole number for the mass number.
Explanation:
those 3
Find the molar mass of Fe_2O_3
2Fe = 2*56 = 112
3O = 3* 16 = 48
Molar Mass = 160 grams
moles= given mass / molar mass
moles = 28 / 160
moles = 0.175 <<<< answer
