The mass ratio of sodium to fluorine in sodium fluoride is 1.21:1. A sample of sodium fluoride produces 28.8 g of sodium upon decomposition. How much fluorine (in grams) is formed?
Solution 33E Isotopes are atoms with the same number of protons but have different number of neutrons. Since the atomic number is equal to the number of protons and the atomic mass is the sum of protons and neutrons, we can also say that isotopes are elements with the same atomic number but ifferent mass number. (a) What isotope is used as the standard in establishing the atomic mass scale Prior to 1961, Scientists used Oxygen as it combines with a lot of things to form oxides. But there were lot of confusions between physicists and chemists and they decided to use Carbon. Since 1961, Carbon is used as it has equal number of protons and neutrons, that is 6 and also, Carbon-12’s atomic mass could be measured particularly accurately compared to the other elements on the periodic table. Hence was used as standard in establishing atomic mass scale. (b) The atomic weight of boron is reported as 10.81, yet no atom of boron has the mass of 10.81 amu. Explain. Atomic weight of an element is determined by taking average of atomic masses and respective relative abundance value of its isotopes. Thus 10.81 atomic weight of Boron is the average value of the number of isotopes and not the mass of an atom.