Spectra and Radiation

• $m_p$ proton mass
• $m_n$ neutron mass
• $Z$ atomic number
  • number of protons in a nucleus
• $A$ atomic mass number
  • number of nucleons
• $N$ neutron number
  • number of neutrons
  • $Z+N=A$
• $_Z^AX$
• isotopes: nuclei that contain the same number of protons but different numebrs of neutrons

27.3

• Photon energy
  • $\boxed{E=hf=h\frac{c}{\lambda}}$
    • $E$ photon energy [J]
    • $h$ Planck’s constant
      • $6.63\times10^{-34}$ [Js]
    • $f$ frequency