Some types of bacteria can reproduce every 20 minutes under ideal conditions. If a single bacterium begins to reproduce at this rate, what is the best estimate of how many bacterial cells there will be after 80 minutes?
8
16
40
80

An empty fuel tank can still contain and therefore can be even more dangerous than one full of liquid fuel.

When balancing a chemical equation:

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?