The current work presents a full calculation of the momentum balance of a bubble during its growth and departure. An experimental investigation of saturated pool boiling from a single artificial nucleation site on a polished copper surface has been performed. The surface was heated from below with a copper rod that was equipped with thermocouples allowing the determination of the heat flux transmitted to the fluid and of the surface temperature. Isolated bubbles grow and departed from the artificial cavity and the bubble dynamics are recorded with a high speed camera. Pure n-pentane was used as the working fluid. Its good wettability on copper and its relatively low surface tension caused the bubble to remain attached to the rim of the nucleation site during the whole growth process. In order to measure the geometric properties of the bubble during its growth, an image processing code was developed using Matlab commercial software. The volume of the bubble, the height of its center of gravity, its curvature profile and the angle of the interface to the horizontal at the triple contact line were determined. A review of the different forces acting on the bubble during its growth was performed. The exact formulation of the momentum variation and of the liquid inertia has been derived. The expression of the buoyancy force acting on the bubble has been developed, and the hypotheses necessary to its calculation have been explicated. The so-called contact pressure force, as part of the buoyancy forces is explained. The importance of the thermocapillary convection and of the viscous stress are discussed. The resultant of the surface tension and adhesion forces acting on the triple line are finally outlined. The calculation of the different forces acting on bubbles during the experiments were performed at each time step of their growth. Several bubbles at different wall superheat conditions (and thus for different growth dynamics) were investigated. The calculation of each term of the momentum balance is detailed. The determination of the momentum variation and the liquid inertia requires an accurate description of the evolution of the volume and its first derivative with respect to time, as well as the evolution of the height of the center of gravity and its first and second time derivatives. The contact pressure force is based on the evolution with time of the curvature radii at the apex of the bubble. The surface tension and adhesion forces rely on the measurement of the angle between the interface and the horizontal surface, which may be different from the contact angle. The calculation of forces reveals the three predominant forces that govern the force balance of the bubble, namely buoyancy contact pressure and surface tension forces. The dynamic forces are negligible in the case of the present experiment. The sensitivity of the forces calculation to the measurement of the base surface and of the angle between the interface and the horizontal surface is outlined.