Electron spin resonance is a technique used to study materials with unpaired electrons. In the presence of an external magnetic field, the magnetic moment of the electron aligns parallel or antiparallel to the field, resulting in the division of energy levels that is directly proportional to the magnetic field. The constant of proportionality that relates a particle's magnetic moment to its angular momentum quantum number and the fundamental quantum unit of magnetism is known as the g-factor. Through the use of ESR and a known magnetic field strength, the g-factor of the electron spin can be approximated using a paramagnetic free radical molecule such as DPPH. The electron g factor for DPPH was determined to be 1.96 ± 0.01 which is inconsistent with the known value for DPPH of 2.0036(2)1 but systematically deactivated due to thermal effects in the apparatus. Paramagnetic substances consist of atoms with unpaired electrons and magnetic moments that are randomly oriented if no external magnetic field is present. If a magnetic field is applied, the magnetic moment of the electron is subjected to a torque such that, however, the angular momentum of an electron cannot have an arbitrary projection along the magnetic field; only full or semi-full screenings are permitted. The potential energy associated with the interaction between magnetic moment and magnetic field is such that the energy levels take on discrete or quantized values ​​highlighted by different projections of the magnetic moments onto the magnetic field. In electron spin resonance, an oscillating magnetic field is used to induce the transition between energy levels. If an oscillating magnetic field is applied between two energy levels such that its frequency corresponds... to the center of the paper... obtained using linear regression. The g factor for DPPH was determined to be 1.96 ± 0.01. The known value of DPPH is 2.0036(2).1 The experimental value does not agree with the known value. The y-intercept in Fig. 5 suggests a systematic error associated with each measurement. This is most likely due to thermal effects that tend to randomize the directions of the magnetic moments and oppose the alignment of the magnetic moment with the magnetic field. A prolonged amount of current flowing through the apparatus would dissipate over time resulting in a temperature change. The temperature dependence of the paramagnetic material is related to Curie's law where is the magnetization of the material, proportional to , and is the Curie constant. An increase in temperature would result in a decrease in the measured magnetic moment and a smaller calculated g-factor.