What does a numerical subscript following an element in a chemical formula mean?

The speed of light is around 6.706×10^8 miles per hour. what is the speed of light in units of miles per minute?

In which environment would primary succession occur? a forest with a few remaining trees after a recent wildfire an area of exposed rock after a glacier melts away beach that is exposed to the air at low tide an abandoned baseball field in a small town

All cells are made of four types of acids, lipids, proteins, and carbohydrates.