C 9.- Far away Figure 3: Two small, neutral conducting spheres, C and D are placed on insulating stands as shown(figure 3). 109 electrons are transferred from C to D, calculate; 1. the charge on (a) C and (b) D (2 marks) 2. if the electrostatic force between the two spheres is 3.56 x 109 N, calculate the distance between their centers. 1 mark 3. If the distance between their centers is increased to 0.5 calculate the electrostatic force between the spheres. 1 mark 4. Charged particles are electrons and protons; true or false (1/2 mark) 5. the subatomic particles which carry the two known charges are called ....... and...... (1/2 mark) D