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How We Calculate The Mass of A Single Carbon C-12 Atom?

October 9th, 2008

Chemistry Tutor Help - Chemistry Problem

If the mass  of electrons = 9.1093897.10^-31 kg, protons = 1.6726430.10^-27 kg, and neutrons = 1.674954.10^-27 kg. Calculate the mass of a single atom Carbon C-12?

Chemistry Tutor Problem Solving

From the periodic table of atoms we know that carbon-12 has 12 electrons, 12 protons, and 6 neutrons thus to find the mass of a single carbon atom we just calculate the masses of total species that build carbon atom. thus

Mass of 1 atom C
= (12x mass of e-) + (12x mass of protons) + (6x mass of n)
= (12 x 9.1093897.10^-31 kg ) + (12 x 1.6726430.10^-27 kg ) + (6×1.674954.10^-27 kg)
= 3.0.10^-26 kg

we can compare from the other way, 1 mole of Carbon has the mass of 12.01 g, since 1 mole of atom has 6.022.10²³  molecules thus:

mass of 1 atom C
= 12.01 /6.022.10²³
= 2.10-²³ g
= 2.10-²⁶ Kg

Entry Filed under: Stoichiometry