How is lightning formed in the cloud and how does it reach the ground?

The most used theory for this question is that when ice and water particles collide in clouds they get charged and make the lightning. lighter particles tend to be positively charged and end up near the top of the cloud, while negatively charged particles end up at the bottom of the storm. The charge on the ground is positive and the negative charge from the clouds enhances it causing an electrical bolt. The bolt than travels at an extreme rate of 60,000 miles per second. This speed and the heat of which the lightning gives off breaks the speed of sound and causes thunder.