Respuesta :
Answer:
0.0423 amu.
Explanation:
- Li atom has 3.0 protons and 4.0 neutrons.
- The mass of Li = mass of protons + mass of neutrons.
- The mass of protons = (3)(1.0073 amu) = 3.0219 amu.
- The mass of neutrons = (4)(1.0087 amu) = 4.0348 amu.
- The mass of Li = mass of protons + mass of neutrons = 3.0219 + 4.0348 = 7.0567 amu.
- The mass defect of Li = the mass of Li - the atomic mass of Li = 7.0567 - 7.0144 = 0.0423 amu.