Radioactive Carbon 14 (atomic number 6) is produced in the atmosphere when a neutron is absorbed by Nitrogen 14 (atomic number 7). Write the reaction and write its Q-value.
The reaction can be written as follows:
N-14 + n -> C-14 + H-1
In this reaction, a nitrogen-14 atom (N-14) absorbs a neutron (n) and is converted into a carbon-14 atom (C-14) along with a hydrogen-1 atom (H-1) as a byproduct.
To determine the Q-value of the reaction, we need to calculate the difference in mass between the reactants and the products and convert it to energy using Einstein's mass-energy equation (E = mc^2).
The atomic masses of the isotopes involved in the reaction are as follows:
N-14: 14.003074 g/mol
C-14: 14.003241 g/mol
H-1: 1.007825 g/mol
neutron (n): 1.008665 g/mol
To calculate the Q-value, we subtract the mass of the reactants from the mass of the products:
Q-value = (mass of products) - (mass of reactants)
Q-value = [(mass of C-14 + mass of H-1) - (mass of N-14 + mass of neutron)]
Q-value = [(14.003241 g/mol + 1.007825 g/mol) - (14.003074 g/mol + 1.008665 g/mol)]
Q-value = (15.011066 g/mol) - (15.011739 g/mol)
Q-value = -0.000673 g/mol
The Q-value of the reaction is approximately -0.000673 g/mol. The negative value indicates that energy is released during the reaction.