What is the term used to describe the energy needed to get a reaction started?

Imagine a rocket launching from earth and travelling to the moon. in which order would the rocket pass through the layers of the atmosphere? thermosphere, mesosphere, stratosphere, troposphere troposphere, mesosphere, stratosphere, troposphere thermosphere, stratosphere, mesosphere, troposphere troposphere, stratosphere, mesosphere, thermosphere

What causes darkening of the skin as melanin production increases

The same agricultural practices are used in every country of the world. select the best answer from the choices provided t f