1. The problem statement, all variables and given/known data You have two inflated balloons. You rub them against your hair and hang them as shown in the figure. The length of the strings is 50 cm and the angle between them is 50°. For each balloon, what is the percentage of atoms that are ionized? Provide a rough estimate. You may find necessary information from the internet. 2. Relevant equations Coulomb's law 3. The attempt at a solution I've tried to find a information about that underlined sentence, but I couldn't find any meaningful information that I can apply to this problem. Is there any formula type relationship between electric force and 'percentage of atoms that are ionized in object'?