Each baryon consists of three quarks represented by small circles within the larger circle. | |
The pluses and minuses in each quark represent the charge of each quark where each plus represents 1/3 of a charge and each minus represents -1/3 of a charge. | |
To be a baryon, the sum of all the charges has to equal an integer (e.g.,-1, 0, 1 ). In the example, the sum is zero shown in the upper right corner. |